Notes for Distance Learning

8/12/2019 Notes for Distance Learning

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MANAGEMENT INFORMATION SYSTEMS:

IT = Computer Technology + Hardware + Software + Telecommunication

Telecommunication is electronically operated communication through wires or wireless like

telegraph, telephone, television.

Information Technology is a set of tools that helps you work with information and perform

tasks related to information processing.

What is MIS?

Today is the information age- a time when knowledge is power. Today, more than ever,

businesses are using information (and information technology) to gain and sustain a competitive

advantage.

In the information age, management information system is a vitally important topic. Why?

Because management information systems deals with the coordination and use of three very

important organizational resources- information, information technology, and people.

Formally, we define MIS as follows:

MIS: deals with the planning for, development, management, and use of information

technology tools to help people perform all tasks related to information processing and

management. In that definition, you can find three key resources- information, information

technology and people. That is, people or knowledge workers use information technology to

work with information. The thing you need to remember is that the sole focus of MIS is not

technology. Technology is a set of tools that enables you to work with information. People and

information are the most important resources within the MIS, not technology.

An ‘MIS’ to be any system that provides people either data or information relating to an

organization’s operations. Management information system support the activities of

employees, owners, customers, and other key people in the organization’s environment (either by

efficiently processing data to assist with the transaction work load or by effectively supplying

information to authorized people in a timely manner). For example, the transaction processing



(data processing) systems that perform accounting and clerical functions are information

systems.

An 'MIS' is a planned system of the collecting, processing, storing and disseminating data

in the form of information needed to carry out the functions of management. In a way it is a

documented report of the activities those were planned and executed. According to Philip Kotler

"A marketing information system consists of people, equipment, and procedures to gather, sort,

analyze, evaluate, and distribute needed, timely, and accurate information to marketing decision

makers."

We use the term information technology or IT to refer to an entire industry. In actuality,

information technology is the use of computers and software to manage information. In some

companies, this is referred to as Management Information Services (or MIS) or simply as

Information Services (or IS). The information technology department of a large company

would be responsible for storing information, protecting information, processing the information,

transmitting the information as necessary, and later retrieving information as necessary.

An organized approach to the study of the information needs of

an organization's management at every level in making operational, tactical, and strategic

decisions. Its objective is to design and implement procedures, processes,

and routines that provide suitably detailed reports in an accurate, consistent, and timely

manner.

In a management information system, modern, computerized systems continuously

gather relevant data, both from inside and outside an organization. This data is then processed,

integrated, and stored in a centralized database (or data warehouse) where it is constantly

updated and made available to all who have the authority to access it, in a form that suits their

purpose.

OR

MIS (management information systems) is a general term for the computer systems in an

enterprise that provide information about its business operations. It's also used to refer to

the people who manage these systems. Typically, in a large corporation, "MIS" or the

"MIS department" refers to a central or centrally-coordinated system of computer

expertise and management.

http://en.wikipedia.org/wiki/Philip_Kotler






In the beginning, business computers were used for the practical business of computing the

payroll and keeping track of accounts payable and receivable. As applications were developed

that provided managers with information about sales, inventories, and other data that would help

in managing the enterprise, the term "MIS" arose to describe these kinds of applications.

Overview:

Initially in businesses and other organizations, internal reporting was produced manually and

only periodically, as a by-product of the accounting system and with some additional statistic(s),

and gave limited and delayed information on management performance. Data was organized

manually according to the requirements and necessity of the organization. As computational

technology developed, information began to be distinguished from data and systems were

developed to produce and organize abstractions, summaries, relationships and generalizations

based on the data.

Early business computers were used for simple operations such as tracking sales or payroll data,

with little detail or structure. Over time, these computer applications became more

complex, hardware storage capacities grew, and technologies improved for connecting

previously isolated applications. As more and more data was stored and linked, managers sought

greater detail as well as greater abstraction (concept, idea) with the aim of creating entire

management reports from the raw, stored data. The term "MIS" arose to describe such

applications providing managers with information about sales, inventories, and other data

that would help in managing the enterprise.

Types

Most management information systems specialize in particular commercial and industrial

sectors, aspects of the enterprise, or management substructure.

Management information systems (M IS) : produce fixed, regularly scheduled reports based

on data extracted and summarized from the firm’s underlying transaction processing

systems to middle and operational level managers to identify and inform structured and

semi-structured decision problems.

Decision suppor t systems (DSS) are computer program applications used by middle

management to compile information from a wide range of sources to support problem

solving and decision making.

http://en.wikipedia.org/wiki/Computer_application

http://en.wikipedia.org/wiki/Hardware

http://en.wikipedia.org/wiki/Computer_data_storage

http://en.wikipedia.org/wiki/Islands_of_automation

http://en.wikipedia.org/wiki/Islands_of_automation

http://en.wikipedia.org/wiki/Computer_data_storage

http://en.wikipedia.org/wiki/Hardware

http://en.wikipedia.org/wiki/Computer_application



Executive in formation systems (EIS) is a reporting tool that provides quick access to

summarized reports coming from all company levels and departments such as accounting,

human resources and operations.

Marketing information systems are MIS designed specifically for managing

the marketing aspects of the business.

Office automation systems (OAS) support communication and productivity in the enterprise

by automating work flow and eliminating bottlenecks. OAS may be implemented at any and

all levels of management.

School management inf ormation systems (MIS) cover school administration, often

including teaching and learning materials.

Old Information Technology trends:

In relative terms, it wasn't long ago that the Information Technology department might have

consisted of a single Computer Operator, who might be storing data on magnetic tape, and then

putting it in a box down in the basement somewhere.

Modern Information Technology Departments:

In order to perform the complex functions required of information technology departments

today, the modern Information Technology Department would use computers, servers, database

management systems, and cryptography (Secret writing). The department would be made up of

several System Administrators, Database Administrators and at least one InformationTechnology Manager. The group usually reports to the Chief Information Officer (CIO).

A) INFORMATION AS A KEY RESOURCE:

Information is important for several reasons for today, two of which we have already stated.

First, information is one of the three key components of management information systems along

with information technology and people. Secondly, we are in the “information” age, a time when

knowledge is power. And knowledge comes from having timely access to information andknowing what to do with it.

Let’s first define data, information, and business intelligence and give an example to understand

them better. Finally, we’ll discuss the elusive term knowledge.



Data versus Information

Raw facts and figures are called data and information is the arranged and meaningful form of

data.

Data represents facts of any kind. In the process of recording important particulars of any event,

it is the discretion of the management, what should be recorded and how it should be presented.

However when this data is processed or reformatted, it becomes information. Information is a

subset of data which adds to the knowledge.

Information should be relevant so that it is valuable for the recipient. Although the processed

form of information is more valuable than the raw form of data, still all information is not of

value for everyone.

Distributing common information to every one may result in waste of time and confusion.

Irrelevant information has no value.

Data are raw facts that describe a particular phenomenon such as the current temperature, the

price of a movie rental, or your age. (Actually, the term data is plural; datum is singular.)

Information is data that have a particular meaning within a specific context. The current

temperature becomes information if you’re deciding what to wear; in deciding what to wear, the

data describing the price of a movie rental are not pertinent information.

Business intell igence (BI) is collective information — about your customers, your competitors,

your business partners, your competitive environment, and your own internal operations — that

gives you the ability to make effective, important, and often strategic business decisions.

Consider Figure 1.2. In the left image is a single Excel cell containing the number 21; let’s

assume that’s your age. That is a piece of data— some sort of fact that describes the amount of

time you have been alive. Now let’s create a list of customers for a business that contains the age

of each customer (the right portion of Figure 1.2). This is potential information since your

business can use it. Notice that you can create an average, find the ages of the youngest and

oldest customers, and build a frequency distribution of customers by age.



Now, look at Figure 1.3. There you’ll see an Excel workbook containing many pieces of

information for each customer. This is business intelligence (often referred to simply as BI).

What does this mean? Take a careful look at some of the columns of information.

For each customer, we know the preferred salesperson. We can also see the number of coupons

each customer has used. Now we can start to derive more meaningful information — business

intelligence. We can compare how men and women use coupons. We can derive the customer

average age by preferred salesperson.

Notice how data, information, and business intelligence all build on each other. Information is a

more complete picture of multiple data points; in our example, an age was a single piece of data

while information was the collective ages of all customers. Business intelligence extends that

information to include gender behavior, the use of coupons, preferred salespersons, and total

purchases. And knowledge builds upon all of those. You acquire knowledge in a business or field

through practice over time using information and intelligence. You will understand better what

we mean by knowledge as we go along.



Time: *Having accessto information when

you need it

*Having information

that describes the time

Form: *Audio, video,text, images, etc

*Free of errors

Locati

on: Access

toinform

ation

Personal Dimensions of Information

As a knowledge worker, you work with and produce information. As you do, you can consider it

from three points of view or dimensions: Time, Location, and Form

The Time Dimension:

The time dimension of information encompasses two aspects:

1) Having access to information when you need it and

2) Having information that describes the time period you’re

considering.

The first really deals with timeliness. Information can become

old and obsolete. For example, if you want to make a stock

trade today, you need to know the price of stock right now.

if you have to wait a day to get stock prices, you may not

survive in the dynamic market. It’s no wonder that over

one-third of all stock transaction occur over internet.



The second time aspect deals with having information that describes the appropriate time period.

For example, most utility companies provide you with a bill that not only tells you of your

current usage and the average temperature but also compares that information to the previous

month and perhaps the same month last year. This type of information can help you better

manage your utilities or simply understand that this month’s high utility bill was caused by

inclement weather.

The Location Dimension:

The location dimension of information deals with having access to information no matter where

are you. This simply means that you should be able to access needed information from an

airplane, in a hotel, at home, in the student center of your campus, at work, or even when driving

down the road. Of course, because of the internet you can be almost anywhere in the world and

access almost any information you need.

To keep certain information private and secure while providing remote access for employees,

many businesses are creating intranets.

(An Intranet is an internal organizational internet that is guarded against outside access by a

special security feature called firewall which can be software, hardware, or a combination of the

two).

So, if your organization has an intranet and you want to access information on it while away

from the office, all you need is web browser software, a modem, and the password that will

allow you through the firewall.

The Form Dimension:

The form dimension of information deals with two primary aspects.

1) The first is simply having information in a form that is most usable and understandable by

you___ audio, text, video, animation, graphical, and others.

2) The second deals with accuracy. That is, you need information that is free of errors. Think of

information as you would think of a physical product. If you buy a product and it’s defective,

you become an unsatisfied customer. Likewise, if you receive information that is incorrect,

you’re very unhappy as well.

For all these various information dimensions, you also should be mindful that you provide your

customers with information. Information you provide to your customers should be timely, should

describe the appropriate time dimension, should be accessible from anywhere, in the most usable



form, and free of errors. Information is a valuable resource and also a commodity you provide to

customer. Make sure they get it the way they want it.

DEFINING NEEDS OF INFORMATION:

Decisions are required to be taken in day to day life. No single task in our life can be done

without decision making. For every assignment we undertake, there has to be a process of

making choices.

Whenever we are faced with choices, there is an inevitable need of selecting one particular

course of action. Any task can be done in various ways, but doing it simultaneously through all

possible alternatives is virtually impossible. This necessitates making a reasonable choice from

all the options available.

An example can be taken for a person who wants to go to Islamabad. He can look at following

options.

• Use any of the local bus service available

• Go by train

• Travel by air

As you can see, the decision to be made in this situation is faced with the availability of a set of

combination of alternatives.

• Every decision we take in daily life requires some sort of information about the alternatives

available.

For instance, in the above example certain factors need to be considered before taking a decision.• How urgent it is to reach to Islamabad

• How much time is available to accommodate traveling, since each mode of traveling will take

different time to reach at the same destination?

• Whether bookings are available for the desired day and time.

• Is there any possibility of cancellation of booking or flight or bus service?

• Which bus service or airline to chose from, since various airlines and bus services are having

traveling facilities to Islamabad.

• Without the availability of relevant information, we may take a decision which is wrong or not

to our benefit. For instance if the person does not have complete knowledge of facts he might not

be able to take the right decision.

• Similar is the case with business. Businesses are run by organizations which are in-fact a group

of people. As individuals have choices to choose from, organizations also face various

alternatives in day to day operations, Decisions are made by individuals from the management.



NEED FOR INFORMATION

Information is required in day to day decision making. Without the availability of right quantity

of information at the right time, the process of decision making is highly affected. For this reason

various sources of information are used to extract information. Some of these are:

o Newspapers

o Internet

o Marketing Brochures

o Friends & Relatives

SOURCES OF INFORMATION

Sources of information are generally categorized as primary, secondary or tertiary depending on

their originality and their proximity to the source or origin . For example, initially, findings

might be communicated informally by email and then presented at meetings before being

formally published as a primary source. Once published, they will then be indexed in a

bibliographic database, and repackaged and commented upon by others in secondary sources.

The designations of primary, secondary and tertiary differ between disciplines or subjects,

particularly between what can generally be defined as the sciences and the humanities. For

example,

• The historian’s primary sources are the poems, stories, and films of the era under study.

• The research scientist's primary sources are the results of laboratory tests and the medical

records of patients treated with the drug.

Written information can be divided into several types.

• Primary Sources

• Secondary Sources

• Tertiary Sources

PRIMARY SOURCES

Some definitions of primary sources:

1. Primary sources are original materials on which other research is based.

2. They are usually the first formal appearance of results in the print or electronic literature (for

example, the first publication of the results of scientific investigations is a primary source.)

3. They present information in its original form, neither interpreted nor condensed (Make more

concise) nor evaluated by other writers.

4. They are from the time period (for example, something written close to when the event

actually occurred.



5. Primary sources present original thinking and report on discoveries or share new information.

Some examples of primary sources:

1. Scientific journal articles reporting experimental research results

2. Proceedings of Meetings, Conferences.

3. Technical reports

4. Sets of data, such as census statistics

5. Works of literature (such as poems and fiction)

6. Autobiographies (Life history)

7. Interviews, surveys and fieldwork

8. Speeches

8. Newspaper articles (may also be secondary)

9. Government documents

10. Photographs and works of art

11. Original documents (such as birth certificate or trial transcripts)

12. Internet communications on email, and newsgroups

SECONDARY SOURCES

Secondary sources are less easily defined than primary sources. What some define as a

secondary source, others define as a tertiary (Coming next after the second) source. Nor is it

always easy to distinguish primary from secondary sources. For example,• A newspaper article is a primary source if it reports events, but a secondary source if it analyses

and comments on those events.

• In science, secondary sources are those which simplify the process of finding and evaluating

the primary literature. They tend to be works which repackage, reorganize, reinterpret,

summarize, index or otherwise "add value" to the new information reported in the primary

literature.

Some Definitions of Secondary Sources:

1. Describe, interpret, analyze and evaluate the primary sources

2. Comment on and discuss the evidence provided by primary sources

Some examples of secondary sources:

1. Bibliographies (List of books or articles) (may also be tertiary)

2. Dictionaries and encyclopedias (may also be tertiary)

3. Dissertations (theses) or theses (more usually primary)



4. Handbooks and data compilations (may also be tertiary)

5. History

6. Journal articles, particularly in disciplines other than science (may also be primary)

7. Newspaper and popular magazine articles (may also be primary)

8. Review articles and literature reviews

9. Textbooks (may also be tertiary)

TERTIARY SOURCES

This is the most problematic category of all.

Some Definitions of Tertiary Sources:

1. Works which list primary and secondary resources in a specific subject area

2. Materials in which the information from secondary sources has been "digested" -reformatted

and condensed, to put it into a convenient, easy-to-read form.

Some examples of tertiary sources:

1. Almanacs (An annual publication including weather forecasts) and fact books

2. Bibliographies (may also be secondary)

4. Dictionaries and encyclopedias (may also be secondary)

5. Guidebooks, manuals etc

6. Handbooks and data compilations (may also be secondary)

8. Textbooks (may also be secondary)

CHANGING NEEDS

When needs change, requirements for information change. Information needs of users are

changing as a result of changes in the availability of information content in electronic form.

Changing needs of the users determine the nature of the physical form in which information

content is currently being made available for users’ access and use in electronic information

environments.

Information needs:

• Each user has a different type of information need depending on what he's trying to find and

why he's trying to find it. If we can determine the most common information needs a site's users

have, we can select the few best architectural components to address those information needs.

• For example, if a user is designing a staff directory, we can assume that most users are

searching for items they already have information about. The user already knows exactly what

he's looking for, he has the terms necessary to articulate that need, and he knows that the staff



directory exists and that it's the right place to look. This type of information need would be best

served by employing a search system. So resources should be invested in developing and

maintaining a comprehensive search system.

B) INFORMATION TECHNOLOGY AS A KEY RESOURCE:

Within management Information System (MIS), the second resource is information technology.Formally defined as:

Information Technology is a set of tools that helps you work with information and perform

tasks related to information processing.

So IT includes a cell phone or PDA that you might use to obtain stock quotes, your home

computer that you use to write term papers, large networks that businesses use to connect to

other businesses, and the internet that almost one in every six people in the world currently use.

Basically IT is a valuable set of tools because it benefits you immediately and directly.

Key Technology Categories:

There are 2 basic categories of technology: Hardware and Software.

Firstly let’s we take a review of computer system then will discuss hardware and software.

Computer:

Computer word is derived from “compute” which means calculations. At early stages it is to be

supposed that computer is only a calculating machine, and it can perform only mathematical

functions.

But in technical words we can define computer as:-

A computer is an electronic device, which takes some raw and unprocessed material (calleddata) from a user, then process it according to given methods (called processing) and at the end

it results some processed material (called information).

Hardware:

The mechanical devices that make up the computer are called hardware. Hardware is any part of

the computer you can touch. A computer’s hardware consists of interconnected electronic



devices that you can use to control the computer’s operation, input and output. (The generic term

“device” refers to any piece of hardware)

All hardware falls into one of six categories: input devices, output devices, storage devices, CPU

and RAM, telecommunication devices (telephone, modem, DSL, cable, wireless, or satellite

modem), and connecting devices (parallel ports, connector cords, buses).

Software:

Software is a set of instructions that makes the computer perform tasks. In other words, software

tells the computer what to do. Some program exists primarily for the computer’s use to help it

perform tasks and manage its own resources. Other type of programs exists for the user, enabling

him or her to perform tasks such as creating documents. Thousands of different software

programs are available for use on personal computers.

There are 2 main types of software: Application software (MS-Word, payroll softwares etc) and

system software. Operating softwares and utility softwares are types of System software.

Roles and Goals of Information Technology:

The roles and goals of information technology are many and varied. The major roles and goals of

information technology include:

1) Increase employee productivity

2) Enhance decision making

3) Enable global reach

4) Facilitate organizational transformation

5) Facilitate record keeping

Knowledge of IT is important because:

IT is everywhere

IT can help you to be more productive

IT will enhance your career

IT will give you a word of opportunity



1) Just think about the tasks you per form everyday and the products you use like VCR’s ,

Television, Automobiles , Telephones , and telephone answering machines and even refrigerators

all have IT in them. So it’s part of our life and we can’t escape.

2) Using IT you can increase your productivity at an unbelievable rate. Today’s word processing

software can check your grammar and even correct your spellings while you type.

Presentation graphics software is used to create presentation material. Internet to find research

material the list is almost endless.

3) Your ability to use IT is important to you because it translates into a job skill, and it’s a skill

that all employers are looking for.

4) IT can open a lot of doors for you and it will literally open the world to you. IT tools such as

internet and the World Wide Web now make it possible for you to virtually travel the world and

communicate with people all over the world, obtain information all over the world and learn

about diverse and interesting cultures.

C) PEOPLE AS A KEY RESOURCE:

The single most important resource in any organization is its people. People (Knowledge

workers) set goals, carry out tasks, make decisions, serve customers, and, in the case of IT

specialists, provide stable and reliable technology environments so the organization can run

smoothly and gain a competitive advantage in the marketplace. This discussion is all about you.

You are preparing to be knowledge workers.

Information and technology literacy: In business, your most valuable asset is not technology

but rather your mind. IT is simply a set of tools that help you work with and process information,

but it’s really just a mind support tool set. Technology such as spreadsheet software can help

you quickly create a high quality and revealing graph. But it can’t tell you whether you should

build a bar or a pie graph, and it can’t help you determine whether you should show sales by

territory or sales by salesperson. Those are yours tasks, and that’s why your business curriculum

includes classes in HRM, Accounting, Finance, Marketing, Production and Operations

management.

Nonetheless (Despite of this fact), technology is an important set of tools for you. Technology

can help you to be more productive, efficient, to better understand problems and opportunities.

So it is important for you to learn how to use your technology set. And it’s equally important that

you understand the information to which you are applying your technology tools.

A technology-literate worker is a person who knows how and when to apply technology. The

“how” aspect includes knowing what technology to buy, how to exploit (To use something well



in order to gain as much from it as possible) the many benefits of application software, and what

technology infrastructure is required to get business connected to each other, just to name a few.

In many unfortunate cases, people and organizations have blindly decided to use technology to

help solve some sort of business problems. What you need to understand is that technology is not

a panacea (something that will solve all the problems of a particular situation). You can’t simply

apply technology to any given process and expect that process instantly to become more efficient

and effective. Like if you apply technology to a process that does not work correctly, then you’ll

only be doing things wrong millions of times faster. There are the cases when technology is

not solution. Being a technology literate knowledge worker will help you determine when and

when not to apply technology.

What is Organization?

Basically, an organization is group of people organized to accomplish an overall goal.

Organizations can range in size from two people to hundreds of thousands -- some people might

argue that organizations are even larger. Organizations have an overall goal (or mission) which is

usually subdivided into various other goals (often called strategic goals) that, in total, will

achieve the overall goal of the organization.

An organization is a structure through which individuals cooperate systematically to conduct

business. It is a collection of people working under predefined rules and regulations to obtain a

set of objectives. It is a stable formal social structure. It takes resources from the environment

and processes them to produce outputs.

NEED FOR ORGANIZATION

As the volume of business expands, the need for disciplined approach to managing operations is

required. This results in formulation of organizational structures. The organizational structures

are formulated in order to efficiently manage the business operations. This makes the structures a

relative term to explain and define. Organizations have the freedom to chose / evolve the

structures which best fits the management needs.

An organization’s primary aim is to achieve the objective that it lays down for itself and in

pursuance of which various actions are undertaken. Such objective could be to generate profits or

specific socioeconomic cultural objectives. What ever the objectives are, these activities

interrelate and their occurrence generate a series of events which helps organization achieve its

goal. The regular and timely recording of information is critical to the proper management of

business operations.



ORGANIZATION & INFORMATION REQUIREMENTS

Organizations have various attributes which distinguish them from each other. No two

organizations are similar in all respects. There have to have certain distinctive lines keeping them

unique from each other.

Unique Attributes of organization

Organizations can be distinguished on the basis of various criteria. These are as follows.

• Organizational structure

• Culture of the Organizations

• Management Style

• Decision Making Style

An organization should consider the above mentioned requirements while devising a system

which tailors for specific information needs.

SIZE OF THE ORGANIZATION AND INFORMATION REQUIREMENTS

• Small Organizations

• Medium scale Organizations

• Large Scale Organizations

SMALL ORGANIZATIONS

Small organizations usually have simple management structure. The need invariably grows from

the limited scope and operations of management. Since tasks to be handled are usually limitedand manageable, hence need for introducing more levels is not required. Since operations can be

managed at the top level by one or two members of the senior management, officers from the

lower level of management are not usually involved in decision making. Mostly the interested

party itself is running the business; hence the management is centralized to few people.

Small scale organizations are characterized by:

• Hence the final decisions are centrally taken.

• Information flows and formats are easy to define and change.

• Since information requirements are not extensive, number of documents prepared and

generated will also be few in number.

Examples of Information requirements of Small Organizations

• Day to day transactions

• Daily Sale



• Cash management

• Receivables and Payables

MEDIUM SIZED ORGANIZATIONS

Medium Sized organizations are normally a family ownership run by brothers, father-son. There

are many organizations existing these days which are being run by the family members. The

prime concern may be the trust already fostered among the blood relations but this might give

rise to informal relationship among them. Since all critical managerial positions are usually

controlled by the family members, information is structured only to the extent of external

reporting. The level of reporting that could meet the information needs of the clients is best

suited for such an organization.

Medium sized organizations are run under direct supervision of the family members so it is

characterized by:

• In it family members rarely extends to segregation of duties and delegation of authority.

• Centralized decision making

• Above mentioned structure rarely changes with complexity and dynamism of environments.

Information requirements of medium sized organizations

As size of the organization increases, the importance of planning for information also increases.

The planning on long-term basis also helps in monitoring of information against planning

LARGE ORGANIZATIONS

Usually such organizations are characterized by large scale of operations. Various criteria can be

used for this purpose.

• Number of employees

• Amount of turnover

• Number of branches

• Profit size

• Value of assets

• Number of businesses the organization is working in With such large size of organizations,

management structure needs to be multi- tiered for efficient and strong control. This leads to

formulation of many departments, management levels, designations, promotional opportunities

and salary increments. (Example Public companies)



Information requirements of large organizations

With such a large structure, it is inevitable that the detailed planning should be made for proper

management control, for both short term and long term performance measurement against plans /

targets.

NATURE OF THE BUSINESS AND INFORMATION REQUIREMENTS

According to nature there are three types of businesses:

• Manufacturing Sector

• Service Sector

• Trading Sector

MANUFACTURING SECTOR

Manufacturing process involves more than one sub-processes, detailed information is required

before transferring materials for warehousing, manufacturing and sale to final consumer.

Information requirements of manufacturing sector

Management is concerned with the

• Day to day costs

• Production targets

• Quality of the product

• Delivery schedules etc

SERVICE SECTOR

Final product is intangible, so information is critical at various steps, e.g. preparation, delivery

and customer satisfaction. Quality maintenance is an issue which requires structured reporting.

Information requirements of Service Sector

• Quality of service provided.

• Mode of delivery

• Customer Satisfaction

• Time Scheduling

• Resource Management



TRADING SECTOR

Monitoring requires information for each product, e.g.

• Customer profiles

• Customer Comments

• Volume of sales

• Profitability

• Stock movements Manufacturing/Procurement Cycle

• Market needs

Nature of Business & Information Requirements

As the size of organization and scale of operations change, information requirements need to be

adjusted for better monitoring to keeping things in control.

Organizational Structure

Pyramid/Tall/Hierarchical organization

A hierarchical organization is organization structured in a way such that every entity in the

organization, except one, is subordinate to a single other entity. This is the dominant mode of

organization among large organizations; most corporations and governments are hierarchical

organizations:

• Low number of subordinates per supervisor

• Long chain of command

• Greater number of levels

Flat/Horizontal Organizations

Flat organization refers to an organizational structure with few or no levels of intervening

management between staff and managers. The idea is that well-trained workers will be more



productive when they are more directly involved in the decision making process, rather than

closely supervised by many layers of management.

This structure is generally possible only in smaller organizations or individual units within larger

organizations. When they reach a critical size, organizations can retain a streamlined structure

but cannot keep a completely flat manager-to-staff relationship without impacting productivity.

Certain financial responsibilities may also require a more traditional structure. Some theorize

that flat organizations become more traditionally hierarchical when they begin to be geared

towards productivity.

Following are the characteristics of a flat organization.

• High number of subordinates per supervisor

• Short of chain of command

• Less number of levels

• Eliminates middle level managers

• Decentralizes authority to low level managers

Culture of the Organization

Organizational culture is the specific collection of values and norms that are shared by people

and groups in an organization and that control the way they interact with each other and with

stakeholders outside the organization. Organizational values are beliefs and ideas about what

kinds of goals members of an organization should pursue and ideas about the appropriate kinds

or standards of behavior organizational members should use to achieve these goals. From

organizational values develop organizational norms, guidelines or expectations that prescribe

appropriate kinds of behavior by employees in particular situations and control the behavior of

organizational members towards one another.



Culture is set of Fundamental Assumptions that exist and grow with the organization. It’s not

publicly announced but spoken about within the organization. It is a combination of implicit

values that keep the organization together. It is essential that the employees understand the

culture-What drives the organization.

Management Styles/Decision making Styles

• Authoritative

• Participative

• Mixed

Authoritative

• An Autocratic or authoritarian manager makes all the decisions, keeping the information and

decision making among the senior management. Objectives and tasks are set and the workforce

is expected to do exactly as required. The communication involved with this method is mainly

downward, from the leader to the sub-ordinate; critics such as Elton Mayo have argued that this

method can lead to a decrease in motivation from the employee's point of view. The main

advantage of this style is that the direction of the business will remain constant, and the decisions

will all be similar, this in turn can project an image of a confident, well managed business. On

the other hand, subordinates may become highly dependent upon the leaders and supervision

may be needed. Decisions are taken centrally by the senior management themselves and are

enforced at all levels.

Participative

In a Democratic style, the manager allows the employees to take part in decision-making:

therefore everything is agreed by the majority. The communication is extensive in both

directions (from subordinates to leaders and vice-versa). This style can be particularly useful

when complex decisions need to be made that require a range of specialist skills: for example,

when a new computerized system needs to be put in place and the upper management of the

business is computer-illiterate. From the overall business's point of view, job satisfaction and

quality of work will improve. However, the decision-making process is severely slowed down,

and the need of a consensus may avoid taking the 'best' decision for the business.

Mixed

The approach is a combination of both authoritative and participative style. Input from

employees is taken and respected, final decision is taken by the senior management keeping in

view the views given by the employees.



Decision Making Approach

• Structured

Procedures are predefined for solving routine repetitive problems

• Non-structured

When problems require individual judgment, evaluation and insight varying on case-to-case

basis

DATA VS INFORMATION

Data represents facts of any kind. In the process of recording important particulars of any event,

it is the discretion of the management, what should be recorded and how it should be presented.

However when this data is processed or reformatted, it becomes information. Information is a

subset of data which adds to the knowledge.

Information should be relevant so that it is valuable for the recipient. Although the processed

form of information is more valuable than the raw form of data, still all information is not of

value for everyone.

Distributing common information to every one may result in waste of time and confusion.

Irrelevant information has no value.

INFORMATION QUALITY CHECKLIST

The information can also be ranked in accordance with the qualities it has in it. The experts have

devised certain criteria to evaluate the quality of information. These are stated below:

1. Is it clear who has written the information?

2. Who is the author? Is it an organization or an individual person? Is there a way to contact

them?

3. Are the aims of the information clear?

4. What are the aims of the information? What is it for? Who is it for?

Does the information achieve its aims?

5. Does the information do what it says it will?

Is the information relevant to me?

List five things to find out from the information.

o .......................................................................................

o .......................................................................................

o .......................................................................................

o .......................................................................................



o .......................................................................................

1. Can the information be checked?

Is the author qualified to write the information? Has anyone else said the same things anywhere

else? Is there any way of checking this out? If the information is new, is there any proof?

2. When was the information produced?

Is it up to date? Can you check to see if the information is up to date?

3. Is the information biased in any way?

Has the information got a particular reason for wanting you to think in a particular way?

Is it a balanced view or does it only give one opinion?

4. Does the information tell you about choices open to you?

Does the information give you advice? Does it tell you about other ideas?

Sources of information in Organizations

There can be sources of information both internal and external to the organization. Following is a

list of important sources.



Direction of Information Flow

CONSIDERING INFORMATION FROM AN ORGANIZATIONAL PERSPECTIVE

Organizations must treat information as any other resource or asset. It must be organized,

managed, and disseminated effectively for the information to exhibit quality. Within an

organization, information flows in four basic directions (see Figure 1.4 on the next page):

1. Upward. Upward information flows describe the current state of the organization based on its

daily transactions. When a sale occurs, for example, that information originates at the lowest

level of the organization and is passed upward through the various levels. Along the way, the



information takes on a finer level of granularity. Information granularity refers to the extent of

detail within the information. At lower organizational levels, information exhibits fine

granularity because people need to work with information in great detail. At the upper

organizational levels, information becomes coarser because it is summarized or aggregated in

some way. That is, strategic managers need sales by year, for example, as opposed to knowing

the detail of every single transaction.

2. Downward. Strategies, goals, and directives that originate at a higher level are passed to

lower levels in downward information flows. The upper level of an organization develops

strategies; the middle levels of an organization convert those strategies into tactics; and the lower

levels of an organization deal with the operational details.

3. Horizontal. Information flows horizontally between functional business units and work teams.

The goal here is to eliminate the old dilemma of “the right hand not knowing what the left hand

is doing.” All units of your organization need to inform other units of their processes and be

informed by the other units regarding their processes. In general, everyone in a company needs

to know everything relevant in a business sense (personal and sensitive data not included).

4. Outward/inward. Information is communicated from and to customers, suppliers,

distributors, and other partners for the purpose of doing business. These flows of information are

really what electronic commerce is all about. Today, no organization is an island, and

outward/inward fl ows can yield a competitive advantage.

Ideal Information Network in an Organization

• Periodically updated / continuously updated – the information should be updated so that

whenever accessed, the user should be fully informed.

• Efficient Processing – data should not be kept unprocessed for long. Timely processing helps

in effective decision making.

• Value driven – the information kept in a computerized system should add value to the user’s

knowledge.

• Audience Centered – every one should receive that part of information that is relevant to the

user.

Conclusion

• Availability of timely and accurate information helps in pro per decision making and meeting

the organizational goals.

• Information should be tailored in accordance with the organization’s culture and structure.



SYSTEMS VS PROCEDURES

Procedure is a defined set of instructions aimed at describing how to proceed in achieving a pre-defined

milestone/target. Systems have collection of predefined procedures related to each other in a sequenced

logical manner in order to collectively achieve the desired results. The system & procedures in all kinds

of environment are subject to internal controls and checks that are necessary to ensure the effectiveness of

the same.

Purpose of Systems & Procedures

The basic purpose behind setting up systems and procedures is to make available information when

required. But when procedures are organized in a logical manner to form systems, the value of

information as an output of a system enhances. When technology is added to the system, scope of a

system changes to include hardware, software and designs linked together in accordance with the

procedures contained in that system to give a purposeful architecture.

Data & Information

Before defining what information systems are? I would like to once again differentiate between data and

information. Data represents facts of any kind. Information is the processed form of data being verified

and substantiated from various sources.

Example

100,000 is a figure which by itself does not add to the knowledge

But when we say 100,000 sales orders, it does add to our knowledge, hence is information.

Generation of relevant information is the objective of every information system. Now we would move

forward with the definition & necessity of information systems.

What are Information Systems?

Interrelated components working together to collect, process, and store and disseminate information

to support decision making, coordination control, analysis and visualization in an organization.

Information systems are implemented within an organization for the purpose of improving the

effectiveness and efficiency of that organization. Capabilities of the information system and

characteristics of the organization, its work systems, its people, and its development and implementation

methodologies together determine the extent to which that purpose is achieved

Manual Vs Computerized Information Systems

Manual IS:

A system in which do not use any computer devices. All data would be kept in other ways, mainly paper.

As a few examples: Before accounts, payroll and spreadsheet applications, people would have worked out

this kind of information on paper. People would have handwritten letters or used typewriters instead of

word processors. Graphs and diagrams would have been drawn by hand instead of using computer

software to do them.



As advancement was made in every field of life, manual information systems were converted to

computerized systems. In manual environment, the concept of transformation was difficult to apply,

Since input of data into records was by itself the output which also included simple computations.

Concept of control mechanism grew stronger as computerized information systems emerged. Now the

concept of Information system exists with the usage and benefits of Computers as an inevitable part.

Advantages of manual based information systems

1) No training costs are needed, as the current system is very easy to use and doesn't need a

skilled employee.

2) There is low set up costs. The shelves and the cabinets all together don't cost more than a

few hundred dollars.

3) There are also no indirect costs. Ex. electricity bills

4) The system is still organized a bit.

What is Computer based Information System (CBIS)?

CBIS is an Information System that uses computer & telecommunications technology to perform its

intended tasks. In CBIS, Information technology (IT) becomes a subset of the Information system.

The terms Information System (IS) and Computer Based Information System (CBIS) with the

extensive use of computers in almost every field renders it inevitable to think of an IS as CBIS.

Why Information Systems?

In modern age, there has been felt a growing need for the use of information systems. Let’s take a look at

what factors increased the importance of efficient information systems.

Emerging Global Economies

High level of foreign trade has resulted in imports and exports which require inter linkage for smooth

coordination. Core business functions (manufacturing, finance and customer support) have been

distributed in different countries. Now the entire world has become a global village. Organizations are

operating at different locations in different countries that are why these companies required a high level of

contact with each other to effectively run the operations of business. This type of coordination and contact

is only possible with computer technology. Using Information systems firms are managing their data and

information from multiple locations to a central database. In this global economy each firm is keeping

record of the other organization’s cost, technology, pricing, core competencies etc.

They need information for:

What price strategies are using their competitors?

What technology is using by them?

What are the procedures under their use?

They need to know the foreign trade policies of different countries etc. This list is almost endless



They require continuous information from ever time changing markets so that they can plan for future

Transforming Industrial Economies

Industrial economies have started merging as knowledge-and-information-based economies.

Manufacturing activities being shifted to low wage countries. More opportunities are available in

education, health care, banks, insurance firms and law firms. More knowledge and information intense

products are being created. Higher commitment expected from customer e.g. overnight package delivery,

world wide reservation systems.

Transformed Business Enterprise

The structure of business enterprise have also changed, initially the organizations used to be

Hierarchical, Centralized, Structured following a Fixed Set of SOP’s. However, now the organizations are

moving towards more Flatter, Decentralized and Flexible structures. Information Technology makes it

convenient and efficient to promote this new culture.

Emerging Digital Firms

Firms where all significant business process and relationships with customers and suppliers and

employees are digitally enabled and key corporate assets are managed through digital firms. This results

in rapid response with more flexibility to survive and getting more global.

A digital firm is one in which nearly all of the organization's significant business relationships with

customers, suppliers, and employees are digitally enabled and mediate. Core business processes are

accomplished through digital networks spanning the entire organization or linking multiple organizations.

Business processes refer to the set of logically related tasks and behaviors that organizations develop

over time to produce specific business results and the unique manner in which these activities are

organized and coordinated. Digital firms involve both time shifting and space shifting. Time shifting

refers to business being conducted continuously, 24x7, rather than in narrow "work day" time bands of 9

a.m. to 5 p.m. Space shifting means that work takes place in a global workshop, as well as within national

boundaries.

Attributes of an IS/CBIS

The attributes an Information System should have, to be worthy of being used by an organization for

meeting its information requirements. Although information requirements may vary from organization to

organization, however common premise is quite the same for many.

• Efficient Processing, including query time

• Large Storage Capacity

• Reduced information Load

• Cross-functional boundaries



• Competitive Tool

• Electronic Document Management/Paper Free environment

Let’s consider each of these one by one.

Efficient Processing

Every transaction affects our records in a number of ways. CBIS helps in updating every change being

triggered in less time and with less effort.

Large Storage Capacity & Instant Access

Efficient and effective decision making requires two aspects

– Availability of processed corporate data – occurrence of every event relating to a company affects

policy making and implementation, thus recording and processing of every data results in huge amount of

information

– Instant access to right chunk of information presented in comprehensible format – both the above

requirements are easy to handle when a well structured information system is in place.

Reduced Information Load

With such huge amounts of information available, managers can feel overloaded, hence taking more time

in decision making. CBIS/IS help to tailor loads of information w.r.t. every manager’s requirements. The

way information is presented can also save time for decision making. Hence, report formats can be

tailored in accordance with the nature of problem being faced.

Cross-Functional Coordination

There are various functions in an organization that need to be managed.

o Manufacturing

o Purchasing

o Warehousing

o Marketing

o Accounts

o Finance

o Human Resource

In every transaction, every department has its own share of responsibility. Thus uncoordinated effort by

every department won’t help in achieving the successful completion of transaction and meeting

commitments. CBIS help in keeping an updated record for easy access by every department in an

organization.

Example

A customer order is received by Sales/Marketing department. Record for customer profitability and

recovery pattern are also kept by sales dept.

• Manufacturing requires

• Customer order in quantitative terms



• Raw material availability for production

• Time available for delivery

• Procurement schedule

• Accounts require an intimation the delivery is made along with the sales invoice

• Customer wants the status of its/his/her order

Competitive Tool

Businesses invest to earn profits or for other non-profit based objectives. There seems no point in pouring

in Co.’s hard earned money on IS if they don’t add to the quality and value of information. Hence

CBIS/IS can and should work to enhance the competitive advantage for the organization.

Paper Free Environment

• Information overload enhances paper work.

• Maintenance of records in hard form has always proven to be a cumbersome task.

• An IS/CBIS should be efficient enough to properly manage of documents electronically.

• Customer orders met through Virtual Private Networks and intranets (to be discussed later).

• Payments made through Electronic payment system.

• Report generation and record analysis gets convenient and easy.

Conclusion

Hence an Information System / Computer Based information system should help an organization in

achieving the above mentioned goals. If put differently, an organization should not proceed with theimplementation of an IS unless it helps in achieving the above goals.



Database:

Database is an organized collection of related data that is stored in an efficient and compact

manner.

The word organized means that data is stored in such a way that the user can use this data easily.

The word related means that a database is normally created to store the data about a particular

topic.

For example if a database is created for students, it will contain data about the students such as

roll no, name, address etc. Similarly, if the database is about the employees of an organization, it

will contain the data of employees such as employees ID, grade and salary etc. All data in

database is arranges in tables.

The word efficient means that the user can search the required data quickly. The word compact

means that the stored data occupies as little space as possible in computer.

Tables:-

Table is the fundamental object of the database structure. The basic purpose of a table is

to store data. A table consists of rows and columns. A table is a very convenient way to store

data. The data in tables can be manipulated easily.

Serial No Name Qualification Email

1 Usman B.SC. [email protected]

2 Abdullah M.SC. [email protected]

3 Ejaz M.SC. [email protected]

Table: Records table.

Rows/Record

Rows are the horizontal part of the table. It is a collection of related fields. For example,

the above table has three rows. Each row contains a record of different person.

2 Abdullah M.SC. [email protected]

A single row/ record

mailto:[email protected]








Columns/ Field

Columns are the vertical part of the table, For example, all values in the above table

under “Name” field make a column.

A single column

Examples of Databases:

Following are some important examples of databases:

1. Phone Directory

Phone directory is a simple example of a database. A phone directory stores the

phone numbers of different persons. Searching a phone number from phone

directory is very easy as all phone numbers are stored in an organized way.

2. Library

A library contains thousands of books. It is very difficult to handle the records of

all these books without database. A database system can be used to store the

records of books, search the required books easily. This database can help for

doing research work.

3. College

A college has many students in different classes. A database may be used to keep

the records of the students, fee transactions, examination information and other

data of the college. It can also store the attendance of the students.

Database Management System

A database Management system (DBMS) is a collection of programs that are used

to create and maintain a database. DBMS is a general-purpose software system that provides the

following facilities:

Name

Usman

Abdullah

Ejaz



1. It provides the facility to define the structure of database. The user can specify data types,

format and constraints for the data to be stored in database.

2. It provides the facility to store data on some storage medium controlled by DBMS.

3. It provides the facilities to insert, delete, update and retrieve specific data to generate

reports etc.

Components of Database Environment

The important components of a database environment are as follows:

1. Repository

A repository is a collection of all data definitions, data relationships, output styles and

report formats etc. All this information is the metadata that is important to manage

database.

2. Database Management System

A database management system (DBMS) is a collection of programs that are used to

create and maintain a database.

3. Database

Database can be defined as an organized collection of related data. The word “organized”

means that data is stored in such a way that user can store, manipulate and retrieve data

easily.

4. Application Program

An application program is program that is used to send commands to the database

management system to manipulate database. These commands are sent to the DBMS

through graphical user interface. The user interface with the application program and the

application program further interacts with the database management system. Two

important application programs are developer 2000 and power Builder.

5. User Interface

The user interface is a visual environment that is used to communicate with the computer.

It consists of menus, buttons and other components. All windows based software use

graphical user interface. The user interface consists of following components. It will

contain forms, menus and reports.



6. Data Administrators

Data administrators are the persons who are responsible of whole information system.

They authorize access to the database as well as coordinate and monitor the use of

database.

7. System Analysts and Application Programmers

System analysts determine the requirements of end users and develop specifications fortransactions. Application programmers implement these specifications and programs.

8. End User

End users are those persons who interact with the application directly. They are

responsible to insert, delete and update data in the database. They get information from

the system as and when required.

Data HierarchyData Hierarchy refers to the systematic organization of data, often in a hierarchical form. Data

organization involves fields, records, files and so on.

A data field holds a single fact. Consider a date field, e.g. "September 19, 2004". This can be

treated as a single date field (e.g. birthdate), or 3 fields, namely, month, day of month and year.

A record is a collection of related fields. An Employee record may contain a name field(s),

address fields, birthdate field and so on.

A file is a collection of related records. If there are 100 employees, then each employee would

have a record (e.g. called Employee Personal Details record) and the collection of 100 such

records would constitute a file (in this case, called Employee Personal Details file).

Files are integrated into a database. This is done using a Database Management System. If there

are other facets of employee data that we wish to capture, then other files such as Employee

Training History file and Employee Work History file could be created as well.

The above is a view of data seen by a computer user.

The above structure can be seen in the hierarchical model, which is one way to organize data in a

database.



In terms of data storage, data fields are made of bytes and these in turn are made up of bits.

Database Approach

Database approach has many advantages over file processing system.

1. Redundancy Control

The data in a database appears only once and is not duplicated. For example the data

of a student in college database is stored in one table. The table can be accessed for

different purposes. For examples, if we want to store the marks of student in a table,

only roll No of the student will be used in second table. The second table will be

connected to the student table for accessing the information about the student as

follows:

Student Table

Roll No Name Address Email Phone

1 Usman Faisalabad [email protected] 727253

2 Abdullah Faisalabad [email protected] 784692

Marks Table

Roll No Subjects Marks

1 Math 98

1 English 87

2 Math 81

2 English 92

In the above figure, the details of the students are stored in student table. The marks table stores

only the Roll No of students. The remaining data is not duplicated. Roll No in the Marks table is

duplicated for joining two tables.

2. Data Consistency

An important benefit of controlling redundancy is that the data is consistent. If a

data item appears only at one place, it is easy to maintain. If it is required to update data the






updating is performed at only one place. The change will automatically take effect at all places

where ever this data is used.

3. Consistency Constraints

Consistency constraints are the rules that must be followed to enter data in database. If

the constraints are not fulfilled, data cannot be entered in database. Database Management

systems provide an easy way to apply different consistency to ensure data consistency. For

example, a constraint can be applied to ensure that the data is always entered in a specific range

etc.

4. Data Atomicity

A collection of all steps to complete a process is known as transaction. Data atomicity

means that either a transaction should take place as a whole or it should not take place at all. It

ensures that the database will always have correct and consistent data. Suppose a user wants to

transfer money from account A to account B. This process consists of two steps:

1. Deduct the money from account A.

2. Add the money to account B.

Suppose that the system fails when the computer has performed the first step. It means that the

amount has been deducted from account A but has not been added to account B. This situation

can make data inconsistent. The database management system does not allow such a situation to

happen. Database management system either executes both steps or does not execute any step.

5. Data Security

Data security is the protection of the database from unauthorized access. The database

management system provides several procedures to maintain data security. The security is

maintained by allowing access to the database through the use of passwords. Not every use of

database system should be able to access all the data.

In some situations, it is required to provide different types of access permission to datafor different users. For example, a data entry operator should only be allowed to enter data. The

chairman of the organization should be able to access or delete the data completely. Database

management system provides different levels of security options for different users.



Disadvantages of Database Approach

Some disadvantages of using database approach are as follows:

1. High Cost of DBMS

A Complete database management system is very large and sophisticated software. It is

expensive to purchase database management software.

2. Higher Hardware Cost

Database management systems are complicated and heavy soft wares. Additional memory

and processing power may be required to run the DBMS. It may require more powerful

hardware.

3. Higher Programming Cost

DBMS is complex software with many features. The programmers need a thorough

knowledge of system to use it to best advantage. If the organization hires experienceddatabase programmers, it has to pay extra cost for this expertise.

4. High Conversion Cost

If an organization converts its records to database, data has to be converted from files to

database system. Because of the different formats used by different systems, it may be a

difficult and time-consuming process. Moreover, the structure and data may also have to be

modified according to the requirements of DBMS.

5. More Chance of Failure

In database management system, all resources and components are centralized. If any of

these components fails, the whole system stops.

6. Complexity & Performance

Database management system is general-purpose software. A complete DBMS has to

perform many tasks that make it complex and complicated software. In some applications,

DBMS may run less efficiently as compared to file processing system.

Difference between File and Database Approach

The difference between File and Database approach is as follows:

File-based approach Database approach

1. The programs and data are

interdependent.

1. The programs and data are independent

of each other.

2. The data may be duplicated in different 2. The data is not duplicated and appears



files that cause data redundancy. only once.

3. The same data in different file may be

different that creates inconsistency.

3. The data appear only once so it is always

consistent.

4. The data is separately stored in various

files and it is different for application to

retrieve the appropriate data.

4. The data is stored in tables which are

linked together. The applications can

retrieve the required data easily.

5. The data is distributed in many different

files and cannot be shared.

5. The data is stored at one place and can

be shared easily.

6. It is difficult to apply data integrity

checks on files.

6. Database approach provides many

constraints for data integrity.

7. It provides poor security as the data is

widely spread.

7. It provides many procedures to maintain

data security.

8. It is difficult to maintain as it provides

less controlling facilities.

8. It provides many facilities to maintain

the programs easily.

9. It is less complex system. 9. It is very complex system.

10. The cost is very less than DBMS. 10. The cost is much more than file system.

11. One application can fail without

affecting the others.

11. All application relying on database fails

if the database fails.

Application Programs

An application program is program that is used to send commands to the database management

system to manipulate database. These commands are send to DBMS through graphical user

interface. The user interacts with the application program. The application program further

interacts with the database management system. Two important application programs are

developer 2000 and power builder.

Relationship of Application programs and DBMS:

A database application is developed by using both application program and database

management system. The application program contains the user interface. The user uses this

interface for communicating with the database management system to manipulate database. The

application program is also called front-end and the database is know as back-end.

The relation of application program and database management system is very important. When a

database program is developed, a way of communication with the program is required by the



user. The user cannot use the database directly. An easy and simple interface is required so that

the user can easily use the database.

Another important relationship of DBMS and application program is that it is used to produce

effective and informative reports in application programs. These reports are very important for

any organization for taking different decisions about business.

Range of Database Application:

The range of database application is as follows:

Personal computer database:

Personal computer database are specially designed for single user. The user may be using stand-

alone desktop computer or laptop. The representatives of a medical company may use laptop

computers when working in the market. This computer may use a simple database application in

which the records of customers are stored. Some important decisions about the development of

personal computer database applications are as follows:

It should be purchased or developed within the organization?

It should be developed by end-user or professional in information systems?

Required data and design of database

Selection of DBMS for database application Accuracy of data in personal computer

database

Personal computer databases are widely used. A problem with this database application is that itis difficult to share quickly. For example, if the head of medical company wants to get complete

information of his customers, it cannot be done quickly as it is stored on the laptop computers of

different representatives.

Workgroup Database:

A workgroup is a team of people who work on the same project collectively. A workgroup

normally consists of less than 25 people. A type of database that is specially designed to support

workgroups is known as workgroup database.

The people in workgroup are connected with one another through local area network (LAN).

The database is stored on a central computer called server. All members of the workgroup can

share this database.

Workgroup databases provide many facilities but arise some problems also. The main problems

are of security and integrity of data when the data is updated concurrently. Some important

decisions about databases are as follows:



Database optimization to satisfy requirements of different members of workgroup

Concurrency control

Decision about the location of different operations i.e. on server or workstation

Department Database:

A functional unit in an organization is known as department. An organization may have

marketing, production and accounting departments. A department normally consists of 25 to 100

people. Department databases are specially designed to support the functions of a department.

Some important decisions about department databases are as follows:

Databases design for efficient performance to handle a large numbers of users and

transactions

Proper security to protect data against unauthorized access

Database tools for complex environment

Ensure data redundancy and consistency if data is used in different departments

The need for distributed database if users are geographically away from one another

Enterprise Database:

A type of database that is specially to support the functions of a whole organizations or many

department of an organization is known as enterprise database. The most important enterprise

database is known as data warehouse. The contents of a data warehouse are derived from many

operational database like personal computer, workgroup and department databases.

Suppose a university has many departments like CS, Biology, and Agriculture etc. Each

department uses a department database to maintain the functions of department. The vicechancellor needs to get the information of different departments frequently. In order to satisfy

this requirement, a data warehouse can be developed for the whole university in VC office. The

data warehouse will extract the databases of different departments periodically. Some important

decisions about department databases are as follows:

Distribution of data among various locations in the corporate structure

Maintenance of standards for data names, definitions, and formats



Types of users

There are different types of user that play different roles in a database environment. Following is

a brief description of these users:

Application Programmers:Application programmer is a professional who writes computer programs in a high level

language. These programs can be used to interact with databases. Application programmer

designs application programs according to the requirements of the users. He works according to

the specification provided by the systems analyst.

End users:

End users are those persons who interact with the application directly. They are responsible to

insert, delete and update data in the database. They get information from the system as and when

required. Different types of end users are as follows:

Naive users: Naive users are the users who have no technical knowledge about the

DBMS. They use database through application programs using simple user interface.

They perform all operations by using simple commands provided in user interface. The

data entry operator in an office is responsible for entering records in database. He

performs this task by using menus and buttons etc. He does not know anything about

database or DBMS. He interacts with database through application program.

Sophisticated Users: Sophisticated users are the users who are familiar

Database Administrator:

Database administrator is the most technical user. He is responsible for managing the whole

database system. He designs, creates and maintains the database. He manages the users who can

access this database and controls integrity issues. Some important functions of a database

administrator are as follows: Installation of software

Monitoring of database system

Solution of any problem that occurs in the database system

Taking regular backups of database

Restoring the system in case of any problem or system crash

Relational Model:



In a relational model, data is stored in relations. Relation is another term used for table. A

table in a database has a unique name that identifies its contents. Each table can be called an

intersection of rows and columns. An important property of a table is that the rows are

unordered. A row cannot be identified by its position in the table. Every table must have a

column that uniquely identifies each row in that table.

Relational Database Terminology:

Some important terminologies used in relational database model are as follows:

Primary key

Relation

Figure: Database Terminology

Relation: In a relational model, data is stored in relations. Relation is another term used for

table. Following is an example of a relation.

Figure: An example of Relation

Registration No Name Class

96-AG-1940 Nadeem Khalil Msc

96-AG-1889 Ejaz Saeed Msc

96-AG-1991 Anjum Msc

96-AG-1996 Abdullah Msc

Registration No Name Class



96-AG-1991 Anjum Msc

96-AG-1996 Abdullah Msc

Domain

Reg. noDomain

Name

Domain

Class

Tu les



Tuple: In a relational model, every relation or table consists of many tuples. Tuples are also

called records or rows.

Figure: Two tuples of a Relation

Attributes: An attribute is a named column of a relation. Attributes are also called

characteristics. The characteristics of the tuple are represented by attributes or fields.

Figure: Attributes of a relation

Domain: A domain is a collection of all possible values of one or more attributes. For example,

the value in the field “Class” can be the name of any taught classes. It is known as class domain.

Similarly, Registration domain is a collection of all possible Registration numbers.

Degree: The number of attributes is called the degree of that relation.

Cardinality: The number of tuples is called the cardinality of that relation.



Ejaz Saeed

Anjum



System Development Life cycle

Planning for System Development

The management should prefer to have a plan for IT development so as to help it to take various

software development projects in a structured way. At the very start, planning is done by the

management regarding following issues

• Scope of software development – certain selected areas or the entire organization.

• How to get the project done – in-house committee or hired consultants.

• How much resource and time commitment can be made?

• Any written policy on which model is needed to be followed for software development.

IT planning provides a structured means of addressing the impact of technologies, including

emerging technologies, on an organization. Through the planning process, relevant technologies

are identified and evaluated in the context of broader business goals and targets. Based on a

comparative assessment of relevant technologies, the direction for the organization can be

established. Business planning is an accepted responsibility of management. Plans provide a

direction and framework for action.

Phases of IT planning

Although information technology plans are unique, the planning process and the underlying

activities are similar.

• Orientation -- This start-up phase is required to establish the scope of the plan and the

methodology and techniques to be applied

• Assessment -- Major steps in this phase are

• Confirm business direction and drivers;

• Review technology trends; outline future requirements;

• Inventory (list or record) existing information systems; and

• Develop an assessment of what is needed.

• In the concluding step of this phase there should be a well-developed assessment of the currentand future business needs,

• Strategic Plan -- This phase commences with developing the vision and desired future

positioning of information technology within the organization.

• Tactical Plan -- The selected strategies are divided into a series of projects which are

scheduled for implementation depending upon relative priorities and resource availability. The

planning process is concluded by recommending a monitoring and control mechanism.



What is System Development?

System development refers to the structuring of hardware and software to achieve the effective

and efficient processing of information. Information systems are developed keeping in view the

needs to be met. There can be two reasons for system development.

• A manual information system is to be computerized.

• An already computerized information system is to be replaced with a system that addresses the

growing and changing needs of the organization or the old system has become too slow or there

are newer more efficient and user friendly development tools are available.

In both the above mentioned situations, the phases followed for system development would be

the same.

The extent of system study, analysis & design may depend on the fact whether the existing

system is manual or computerized. To develop systems, various development models or

techniques are deployed. Let us understand why these development models are used.

Models Used for System Development

Initially software development consisted of a programmer writing code to solve a problem or

automate a procedure. Nowadays, systems are so big and complex that teams of architects,

analysts, programmers, testers and users must work together to create the millions of lines of

custom-written code that drive our enterprises. To manage this, a number of models for system

development have been created. The most famous of these models is the system development

lifecycle model (SDLC) or Lifecycle Models.

Systems Development Life Cycle (SDLC)

The systems development life cycle (SDLC) is a conceptual model used in project management

that describes the stages involved in an information system development project, from an initial

feasibility study through maintenance of the completed application. SDLC is also known as

information systems development or application development. Various SDLC methodologies

have been developed to guide the processes involved, including the waterfall model (which was

the original SDLC method); rapid application development (RAD); joint application

development (JAD); the fountain model; the spiral model; build and fix; and synchronize-and-

stabilize.



Often, several models are combined into some sort of hybrid methodology. Documentation is

crucial regardless of the type of model chosen or devised (set up, develop, create) for any

application, and is usually done in parallel with the development process. Some methods work

better for specific types of projects, but in the final analysis, the most important factor for the

success of a project may be how closely the particular plan was followed.

In general, an SDLC methodology follows these steps:

1. If there is an existing system, its deficiencies are identified. This is accomplished by

interviewing users and consulting with support personnel.

2. The new system requirements are defined including addressing any deficiencies in the

existing system with specific proposals for improvement.

3. The proposed system is designed. Plans are created detailing the hardware, operating

systems, programming, and security issues.

4. The new system is developed. The new components and programs must be obtained and

installed. Users of the system must be trained in its use, and all aspects of performance

must be tested. If necessary, adjustments must be made at this stage.

5. The system is put into use. This can be done in various ways. The new system can phased

in, according to application or location, and the old system gradually replaced. In some

cases, it may be more cost-effective to shut down the old system and implement the new

system all at once.

6. Once the new system is up and running for a while, it should be exhaustively evaluated.

Maintenance must be kept up rigorously at all times. Users of the system should be kept

up-to-date concerning the latest modifications and procedures.

Need Assessment

Information systems are usually developed on need-basis, that is, problems and opportunities

arise and render system development necessary. In this phase the stakeholders must attempt to

come to some understanding of the nature of the problem or opportunity they are addressing.

Should formal terms of reference be prepared and approved by the steering committee or project

committee? This depends on the size, impact and cost of the system being prepared. The TOR

“(short for The onion router) is a system intended to enable online anonymity (secrecy)” usually

covers following aspects.

• Investigation on existing system

• Definition of system requirements

• Specifying performance criteria for the system

• Detailed cost budget



• Draft plan for implementation

If the problem is decided to be addressed and the level of acceptance that exists among the

stakeholders on the need of change, the level of technological uncertainty the proposed solution

to the problem/opportunity has. The most critical phase is the agreement of the stakeholders on

the definition of problem and parameters of solution.

Entry and Feasibility Study

The purpose of this phase is to obtain a commitment to change and to evaluate whether cost

effective solutions are available to address the problem or opportunity that has been identified.

Following examples can be considered to explain this situation.

• Say a problem has been recognized by a group of users. They believe they can design and

implement a solution themselves using a high level language. Their proposed system will not

have little impact on others within the organization, nor will it be material from the viewpoint of

the overall organization. In this situation, the users are already motivated to bring about change.

Thus activities to accomplish successful entry are minor or unnecessary.

• On the other hand, consider a solution where potential solutions will have a widespread impact

on the overall organization. Activities to accomplish successful entry are now critical.

Information systems professionals must seek to establish themselves as legitimate change agents

among the stake holders. Moreover they must seek to foster among the stakeholders a

commitment to change. If potential solutions will have a significant impact on task and social

systems, a spirit of collaborative analysis and evaluation among stakeholders must be developed.Once the entry is successful, a preliminary study can be carried out to evaluate the feasibility of

the new system. A Feasibility study team should be constituted

• Draw representatives from the departments affected by the project

• At least one person must have a detailed knowledge of computers and systems design (called

system analyst).

• At least one person should have a detailed knowledge of

1. The organization

2. How current system operates

3. Information needs of the system

4. Defects in the existing system

• Consultants from the outside



Key Areas of Feasibility

Following aspects/criteria can be covered in a feasibility study.

• Technical Feasibility – is the available technology sufficient to support the proposed project?

Can the technology be acquired or developed?

Electricity

Machinery

• Response times – time between request and execution

• Volume of transactions which can processed within the given time

• Capacity to hold files or records of a certain size

• Number of users supported without execution

• Operational Feasibility – compliance and adjustability with the way organization works with

attitude to change or chains of command.

• Can the input data be collected for the system?

• Is the output usable?

• Economic feasibility – Do the benefits of the system exceed the costs?

It should be the BEST OPTION among those under consideration for the same purpose.

• Behavioral feasibility – What impact will the system have on the user’s quality of working life?

• Reduction is job stress

• Job satisfaction

• Quality of output by employees

Costs of Proposed System



Other feasibility areas can be:

Managerial Feasibility: Skilled persons

Project team

Availability of resources

Financial Feasibility:

Availability of financeCultural Feasibility: compatibility of the proposed project with

the cultural environment

Safety Feasibility: Minimal adverse effects on the

environment.

Market Feasibility: Market analysis

Competitor analysis

Legal Feasibility: NOC

Judicial papers

Types of System Development Life-Cycle Model

The concept of system development lifecycle model has been explained in various shapes and

forms. The concluding form follows the same spirit except for minor differences.



Popular Software Development Models

The following are some basic popular models that are adopted by many software development

firms

A. Waterfall Model

B. Incremental Model

C. Prototyping Model

E. Rapid Application Development Model

Some other models are (Spiral Modal, Component Assembly Model, JAD)

A. Waterfall model / Classic lifecycle/ Linear SequentialModel

This is also known as Classic Life Cycle Model (or) Linear Sequential Model (or) Waterfall

Method.

The waterfall model is a software development model (a process for the creation of

software) in which development is seen as flowing steadily (gradually, increasingly)

downwards (like a waterfall) through the various phases.

There is various software development approaches defined and designed which are

used/employed during development process of software, these approaches are also referred as

"Software Development Process Models". Each process model follows a particular life cycle in

order to ensure success in process of software development.

One such approach/process used in Software Development is "The Waterfall Model". Waterfall

approach was first Process Model to be introduced and followed widely in Software Engineeringto ensure success of the project. In "The Waterfall" approach, the whole process of software

development is divided into separate process phases. The phases in Waterfall model are:

Requirement Specifications phase, Software Design, Implementation and Testing &

Maintenance. All these phases are cascaded (Rush down in big quantities, like a cascade) to each

other so that second phase is started as and when defined set of goals are achieved for first phase

and it is signed off, so the name "Waterfall Model". All the methods and processes undertaken in

Waterfall Model are more visible.



The stages of "The Waterfall Model" are:

Requirement Analysis & Definition: All possible requirements of the

system to be developed are captured in this phase. Requirements are set of functionalities and

constraints that the end-user (who will be using the system) expects from the system. The

requirements are gathered from the end-user by consultation, these requirements are analyzed for

their validity and the possibility of incorporating the requirements in the system to be

development is also studied. Finally, a Requirement Specification document is created which

serves the purpose of guideline for the next phase of the model.

System & Software Design: Before a starting for actual coding, it is highly

important to understand what we are going to create and what it should look like? The

requirement specifications from first phase are studied in this phase and system design is

prepared. System Design helps in specifying hardware and system requirements and also helps in

defining overall system architecture. The system design specifications serve as input for the

next phase of the model. This phase includes the designing of following elements:

Design of the information flow

• DFD’s (Data Flow Diagrams)

• ERD’s (Entity Relationship Diagram)



• Design of database

• Design of user interface

• Physical design

• Design of hardware & software platform

System Coding, Implementation & Unit Testing: On receiving

system design documents, the work is divided in modules/units and actual coding is started. The

system is first developed in small programs called units, which are integrated in the next phase.

Each unit is developed and tested for its functionality; this is referred to as Unit Testing. Unit

testing mainly verifies if the modules/units meet their specifications.

Integration & System Testing: As specified above, the system is first divided

in units which are developed and tested for their functionalities. These units are integrated into a

complete system during Integration phase and tested to check if all modules/units coordinate

between each other and the system as a whole behaves as per the specifications. After

successfully testing the software, it is delivered to the customer.

Operations & Maintenance: This phase of "The Waterfall Model" is virtually

never ending phase (Very long). Generally, problems with the system developed (which are not

found during the development life cycle) come up after its practical use starts, so the issues

related to the system are solved after deployment (use or operation) of the system. Not all the

problems come in picture directly but they arise time to time and needs to be solved; hence this

process is referred as Maintenance.

Arguments for water fall

• Waterfall model places emphasis on documentation (such as requirements documents and

design documents) as well as source code.

• Other methodologies which save time in software development can de-emphasize

documentation. In such methodologies project knowledge is stored mentally by team members.

Should team members leave, this knowledge is lost, and substantial loss of project knowledge



may be difficult for a project to recover from. Extreme Programming is an example which will

be discussed later.

• Waterfall model is preferred for its simple and arguably more disciplined approach. The model

itself progresses linearly through discrete, easily understandable and explainable "phases" and is

thus easy to understand

Arguments against water fall

• It is argued that it is impossible to get one phase of a software product's lifecycle

"perfected" before moving on to the next phases and learning from them.

For example clients may not be aware of exactly what requirements they want before they see a

working prototype and can comment upon it - they may change their requirements constantly,

and program designers. This is an example of iterative model (to be discussed later)

• Waterfall model advocates more reliance on fixed, static requirements. Designers may not

be fully aware of future implementation difficulties when writing a design for an

unimplemented software product. That is, it may become clear in the implementation phase

that a particular area of program functionality is extraordinarily difficult to implement.

• Another problem is that the waterfall model assumes that the only role for users is in specifying

requirements, and that all requirements can be specified in advance. Unfortunately, requirements

grow and change throughout the process and beyond, calling for considerable feedback and

iterative consultation. Thus many other SDLC models have been developed. The choice of phases differs in various standards and organizations.

As it is very important to gather all possible requirements during the Requirement Gathering

and Analysis phase in order to properly design the system, not all requirements are received at

once, the requirements from customer goes on getting added to the list even after the end of

"Requirement Gathering and Analysis" phase, this affects the system development process and

its success in negative aspects.

The project is not partitioned in phases in flexible way.

As the requirements of the customer goes on getting added to the list, not all the requirements

are fulfilled, this results in development of almost unusable system. These requirements are then

met in newer version of the system; this increases the cost of system development.

Produces excessive documentation and keeping it updated as the project progresses is time-

consuming.

Problems are often not discovered until system testing.



B. Incremental Model

In incremental models, software is built not written. Software is constructed step by step in the

same way a building is constructed. The products is designed, implemented, integrated and tested

as a series of incremental builds, where a build consists of code pieces from various modules

interacting together to provide a specific functional capability and testable as a whole.

The incremental model is a method of software/ Information System development where the

model is designed, implemented and tested incrementally until the product is finished. It involves

both development and maintenance. This model combines the elements of the waterfall model

with the philosophy of prototyping.

Example -An example of this incremental approach is observed in the development of word

processing applications where the following services are provided on subsequent modules:

• Basic file management, editing and document production functions

• Advanced editing and document production functions

• Spell and grammar checking

• Advance page layout

The first increment is usually the core product which addresses the basic requirements of the

system. This maybe either be used by the client or subjected to detailed review to develop a plan

for the next increment.

This plan addresses the modification of the core product to better meet the needs of the customer,

and the delivery of additionally functionality.



Characteristics of the Incremental Model

• The system development is broken into many mini development projects

• Partial systems are successively built to produce a final total system.

• Highest priority requirements tackled early on.

• Once an incremented portion is developed, requirements for that increment are frozen.

• Generates working software quickly and early during the software life cycle.

• More flexible - less costly to change scope and requirements.

• Easier to test and debug during a smaller iteration.

• Easier to manage risk because risky pieces are identified and handled during its iteration.

Disadvantages

• Each phase of an iteration is rigid and do not overlap each other.

• Problems may arise pertaining to system architecture because not all requirements are gathered

up front for the entire software life cycle.

• Larger picture cannot be seen until the entire system is built

• Difficult to break down the total system at early stage of product development to determine

reasonable increments

C. Prototyping Model

1) This is a cyclic version of the linear model. In this model, once the requirement analysis is

done and the design for a prototype is made, the development process gets started. Once the

prototype is created, it is given to the customer for evaluation. The customer tests the package

and gives his/her feed back to the developer who refines the product according to the customer's

exact expectation. After a finite number of iterations, the final software package is given to the

customer.

2) This methodology includes:-

•Listen to the customer.

•Develop a demonstrating (demo) version of the software.

•Evaluate by the customer.

The customer is called at the software engineer/developer’s site or he/she visited to customer in

order to gather the main requirements of the software. The software engineer developed a demo



version of the software and, called the customer at his/her site to evaluate the demo. The

customer and software engineer sits together. The customer provides his feed back about the

demo is to the developer. The developer rebuilds the demo according to the changes and new

requirements inquired by the customer. The customer is again called to re-evaluate the demo and

this process continues until the final version of the software/customer satisfaction.

The prototype model, which is illustrated in the above Figure usually, consists of the following:

1. Analyze the user’s basic requirements.

2. Repeat

•Develop or revise the working prototype to include the requirements that are known at this

stage.

•Allow the user to use the prototype to suggest changes to the requirements. If there are no

major changes, exit the loop.



•Analyze the requested changes with the user.

3. The outcome is usually one of the following:

•The final prototype is used as part or all of the specifications for the formal development of

the system.

•The final prototype is placed into production.

E. Rapid Application Development (RAD) Model

The RAD model is a linear sequential software development process that emphasizes an

extremely short development cycle. The RAD model is a "high speed" adaptation of the linear

sequential model in which rapid development is achieved by using a component-based

construction approach. Used primarily for information systems applications, the RAD approach

encompasses the following phases:

RAD model has the following phases:



Business Modeling: The information flow among business functions is defined by answering

questions like what information drives the business process, what information is generated, who

generates it, where does the information go, who process it and so on.

Data Modeling: The information collected from business modeling is refined into a set of data

objects (entities) that are needed to support the business. The attributes (character of each entity)

are identified and the relation between these data objects (entities) is defined.

Process Modeling: The data object defined in the data modeling phase are transformed to

achieve the information flow necessary to implement a business function. Processing

descriptions are created for adding, modifying, deleting or retrieving a data object.

Application Generation: Automated tools are used to facilitate construction of the software;

even they use the 4th GL techniques.

Testing and Turn over: Many of the programming components have already been tested since

RAD emphasis reuse. This reduces overall testing time. But new components must be tested and

all interfaces must be fully exercised.

Advantages of the RAD methodology:

1) It is flexible and adaptable to changes.

2) Prototyping applications give users a tangible description from which to judge whether

critical system requirements are being met by the system. Report output can be comparedwith existing reports. Data entry forms can be reviewed for completeness of all fields,

navigation, data access (drop down lists, checkboxes, radio buttons, etc.).

3) RAD generally incorporates short development cycles - users see the RAD product

quickly.

4) RAD involves user participation thereby increasing chances of early user community

acceptance.

5) RAD realizes an overall reduction in project risk.

Disadvantages of RAD methodology:

1) Unknown cost of product. As mentioned above, this problem can be alleviated (relieved)

by the customer agreeing to a limited amount of rework in the RAD process. It may be



difficult for many important users to commit the time required for success of the RAD

process.

2) Requires highly skilled and well-trained developers.

Conclusion

All these different software development models have their own advantages and disadvantages.

Nevertheless, in the contemporary commercial software development world, the fusion of all

these methodologies is incorporated. Timing is very crucial in software development. If a

delay happens in the development phase, the market could be taken over by the competitor. Also

if a 'bug' filled product is launched in a short period of time (quicker than the competitors), it

may affect the reputation of the company. So, there should be a tradeoff between the

development time and the quality of the product. Customers don't expect a bug free product but

they expect a user-friendly product. That results in Customer Ecstasy. (Joy, happiness)



Computer Networking

A computer network , often simply referred to as a network , is a collection of computers and

devices connected by communications channels that facilitates communications among users and

allows users to share resources with other users. Networks may be classified according to a wide

variety of characteristics. This article provides a general overview of types and categories and

also presents the basic components of a network.

Purpose

Computer networks can be used for several purposes:

Facil itating communications . Using a network, people can communicate efficiently and

easily via e-mail, instant messaging, chat rooms, telephony, video telephone calls, and

video conferencing.

Shari ng hardware . In a networked environment, each computer on a network can access

and use hardware on the network. Suppose several personal computers on a network each

require the use of a laser printer. If the personal computers and a laser printer are

connected to a network, each user can then access the laser printer on the network, as

they need it.

Shari ng f iles, data, and information . In a network environment, any authorized user can

access data and information stored on other computers on the network. The capability of

providing access to data and information on shared storage devices is an important

feature of many networks.

Shari ng software . Users connected to a network can access application programs on the

network.

Types of networks

Common types of computer networks may be identified by their scale.

3.1 Personal area network

A personal area network (PAN) is a computer network used for communication among computer

and different information technological devices close to one person. Some examples of devices



that are used in a PAN are personal computers, printers, fax machines, telephones, PDAs,

scanners, and even video game consoles. A PAN may include wired and wireless connections

between devices. The reach of a PAN typically extends to 10 meters. A wired PAN is usually

constructed with USB and Firewire connections while technologies such as Bluetooth and

infrared communication typically form a wireless PAN.

3.2 Local area network

A local area network (LAN) is a network that connects computers and devices in a limited

geographical area such as home, school, computer laboratory, office building, or closely

positioned group of buildings. Each computer or device on the network is a node.

The defining characteristics of LANs, in contrast to WANs (Wide Area Networks), include their

higher data transfer rates, smaller geographic range, and no need for leased telecommunication

lines.

3.2.1 Home area network

A home area network is a residential LAN which is used for communication between digital

devices typically deployed in the home, usually a small number of personal computers and

accessories, such as printers and mobile computing devices. An important function is the sharing

of Internet access.

3.3 Campus network

A campus network is a computer network made up of an interconnection of local area networks

(LANs) within a limited geographical area. In the case of a university campus-based campus

network, the network is likely to link a variety of campus buildings including; academic

departments, the university library and student residence halls.

3.4 Wide area network

A wide area network (WAN) is a computer network that covers a large geographic area such as a

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