Mis_notes 4 Th n 5th Unit

8/9/2019 Mis_notes 4 Th n 5th Unit

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UNIT IV

Developing long range information system plan/content of the information system master plan:-

Any master plan has 2 basic parts

1. A long range plan for 3 to 5 years or longer.

2.A short range plan for 1 year.

This short range & long range plan helps in resource

allocation & overall controlling & future forecast. It

helps in step by step execution of all the activities

related to organization. The long range plan provides

general guidelines for direction & the short range

portion provides a basis for specific accountability as

to operational & financial performance

Master development plan contains 4 major

sections:-

(1) information system goals, objective &

architecture(2) inventory of current capabilities

(3) forecast of development affecting the plan

(4) the specific plan

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(1)Information system goals, objective &

architecture:-

(1.1) overall organization goals, objectives &

strategies(1.2) external environment (industry, govt,

customer& supplier)

(1.3) Internal organization constraints such as mgmt

philosophy

(1.4) Assumption about business risks & potential

consequences

(1.5) architecture of the Information system

(2) Current capabilities

(1.1) Inventory of hardware, system software, dbms,

application s/w personnel system

(1.2) analysis of expenses, hardware utilization, s/w

utilization

(1.3) status of the projects

(1.4) Major functional system (Accounting, mkting, hr)(1.5) org. strategies

(1.6) Job classification (programme, operation)

(1.7) skill categories (COBOL, data communication)

(1.8) functional area experience (finance, accounting,

manufacturing)

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(1.9) need for maintenance & revision

(3) Forecast of development affecting the plan

(1.1) new technology comes

(1.2) current roles & regulation(1.3) competitive action

(1.4) tax laws,environmet changes

(4) The specific plan

(1.1) Hardware acquisition, schedule

(1.2) purchased s/w schedule

(1.3) application schedule

(1.4) s/w maintenance & conversion schedule

(1.5) personnel resource requirement & schedule of

hiring & training

(1.6) financial resource required (h/w, s/w personnel)

MODELS FOR IMPLEMENTING LONG TERM

STRATEGIES OF MIS

(1) NOLAN STAGE MODEL(2) THREE STAGE MODEL

NOLAN STAGE MODEL:-

This model was given by NOLAN in 1973-1974. This

model was taken by harward business review. The

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NOLAN stage model is a framework for information

system planning that matches various feature of

information system to stages of growth.

Stages of Growth:-

(1) Initiation

(2) Expansion (or contagion)

(3) Formalization (or control)

(4) Maturity (integration)

Stage- I Stage- II Stage- III

Stage- IV

Initiation Expansion

Formalization Maturity

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Initiation: - Early use of computers by small no. of

users to meet basic organizational needs

Expansion: - Experimentation with & adoption of compulsory by many users. Crisis due to rapid rise in

costs

Formalization: - fully organizational control & rapid

growth in use & apply cost effectiveness, criteria,

centralization control

Maturity: - Integration of applications, better

planning & coordination between information system

& organization

THE THREE STAGE MODEL OF THE PLANNINGPROCESS :-

The 3 stage model of information system planning

developed by Bowman, Davis & Wetherbe

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StrategicPlanning

Organizationalinformation

systemrequirement

analysis

Resourceallocation

comparative cost/benefitreturn on interest(ROI)zero based budgeting(ZBB

portfolio approachsteering committeeranking

Business sys planning (BSP)Critical success

factor (CSF)end/means analysis(E/M)

strategy settransformationstrategic gridstrategic fit (toknow org-alculture)derivation org-al

plan

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GenericActivity

Alternativemethodology


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STRATEGIES FOR THE DETERMINATION OFINFORMATION REQUIREMENT:-

THREE LEVELS OF INFORMATIONREQUIREMENTS:-

(1) Organizational level information requirement

(2) Data base requirement

(3) Application level information requirement

Organizational level information requirement: - in

this level information requirement determination key

role in developing an information system master plan.

The requirements of information are divided into

databases & sub systems or use can say portfolio of

useful development stages. The overall information

architecture is defined & the boundaries & interface of

the individual application subsystems are specified.

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Data base requirement:- Database requirement arise

both from application & users/ad hoc

queries./programs. In this level every information is

defined according to database structure & associatedwith organizational process that requires them.

Application level information requirement:- An

application is a subsystem of the overall information

system structure. it provides information processing for

an org-al unit or org-al activity.

There are 2 types of information system application

requirements:-

(1.) Social requirement

(2.) Technical requirement

Social requirement: - the social or behavioral

requirement, based on job design, specify objective &

assumption such as follows:-

a. work organization, design objectives

b. individual role assumptionc. responsibility assumption

d. org-al policies

Technical requirement: - It is based on the

information needed for the job or task to be

performed. they specify outputs,input,stored data &

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c)brainstorming

d) guided brainstorming

e) group consequences (Delphi method)

Deriving from an existing information system:-1.Existing system that will be replaced by the

new system

2.use similar organization system

3.proprietary system or package

4.description in textbook, handbook, industry

studies

Synthesizing from charters tics of the

utilizing system:-

a) Normative analysis (ex : billing system, object &

variable set one time)

b) critical factor analysis

c) strategy set analysis (ex: sales mix, )

d) process analysis

e) end-means analysisf) decision analysis

g) input process output analysis

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DBMS:-

Collection of interrelated data & programs to access

those data is a DBMS.A software system which performs the functions of

defining, creating, revising & controlling the

database. It provides facilities for retreiving data,

genereating report,revising data defintion ,updating

data & building application.

A Database Management System (DBMS) is a set of

computer programs that controls the creation,

maintenance, and the use of the database with

computer as a platform or of an organization and its

end users . It allows organizations to place control of

organization-wide database development in the

hands of database administrators (DBAs) and other

specialists. A DBMS is a system software packagethat helps the use of integrated collection of data

records and files known as databases. It allows

different user application programs to easily access

the same database. Dbms may use any of a variety

of database models , such as the network model or

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relational model . In large systems, a DBMS allows

users and other software to store and retrieve data

in a structured way.

DATABASE REQUIREMENT:

1. Transaction processing requirement

2. Management requirement

Objectives of DBMS:-

Shareability: An ability to share data resources is afundamental objective of database management. In itsfullest interpretation, this means different people and

different processes using the same actual data atvirtually the same time.

Availability: Availability means bringing the data of anorganization to the users of that data. They systemwhich manages data resources should be easily

accessible to the people within n organization makingthe data available when and where it is needed, and inthe manner and form in which it is needed.

Evolvability: Evolvability refers to the ability of theDBMS to change in response to growing user needs and

advancing technology. Evolvability is the system

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characteristic that enhances future availability of thedata resources.

Adaptability is a more advanced form of Evolvability

in which built in algorithms enable a system to changeitself, rather than having a change made to it.Adaptability involves purposive, self organizing, or self controlling behavior, that is, self regulation toward asingle criterion of success: ultimate, long-term survival.

Integrity: The importance and pervasiveness of theneed to maintain database integrity is rooted in thereality that man is perfect. Destruction, errors andimproper disclosure must be anticipated and explicitmechanisms provided for handling them. The threeprimary facets of database integrity are:

- protecting the existence of the database- Maintaining the quality of the database- Ensuring the privacy of the database.

DBMS has many objectives some of them are asfollows.

1.DBMS give multi-user access2.Give good security to database.3.Give full control to Data4.Gives better hope of porting the code to

other DBMS products. (Good compatibility).

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5.Platform independent.6.Support online documentation7.Keep and maintain proper backups.8.Concurrency control.9.crash recovery10. Complex query support

Functions of DBMS:-

- Database Definition

- Database creation (storing data in a defineddatabase)- Retrieval (query and reporting)- Update (Changing the contents of the database)- Programming User Facilities for systemdevelopment- Database revision and restructuring- Database integrity control- Performance Monitoring

DBMS Functions

Data storage, retrieval, and update;A system catalog that can be queried;Security services;Integrity services.

Additional DBMS FunctionsShared update support;Backup and recovery services;

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Data independence support;Replication support; andUtility services.

Data, Storage, Retrieval, and Update The most important capability of a DBMS.Provides users with the ability to store, retrieve, and

update the data in the database.

CatalogContains descriptions of database components and can

be queried by database users.Provides important information for those who are in

charge of a database, or for those who write programsto access the database.

Shared Update

Allows more than one user to query the same data atthe same time.

Ensures accuracy when several users are updating thesame data in a database at the same time.

Backup and RecoveryProvides a mechanism for recovering the database in

the event that the database is damaged in any way. The process of returning the database to a correct state

is called recovery.Periodically making a copy of the database is called

backup.

Data IndependenceAbility to change the structure of a database with

minimal impact on existing programs includes:

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Using ALTER TABLE to add a column or change theattributes of a column

Using the CREATE statement to create a new table,index or view

Using ALTER TABLE to add or change a relationshipby adding and/or dropping a foreign key

ReplicationA way to manage copies of the same data at multiple

locations.

UtilitiesAssist in the general maintenance of the database:

Permit changes to be made in the database structure.Permit the addition of new indexes and the deletion

of ones no longer needed.Access to DOS, Windows, Linux, and other operating

system services from within the DBMS.

DBMS ARCHITECTURE:-

A commonly used view of data approach is the three-level architecture suggested by ANSI/SPARC (AmericanNational Standards Institute/Standards Planning andRequirements Committee). ANSI/SPARC produced aninterim report in 1972 followed by a final report in

1977. The reports proposed an architectural frameworkfor databases. Under this approach, a database isconsidered as containing data about an enterprise . Thethree levels of the architecture are three different viewsof the data:

1. External - individual user view2. Conceptual - community user view3. Internal - physical or storage view

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The three level database architecture allows a clearseparation of the information meaning (conceptualview) from the external data representation and fromthe

physical data structure layout. A database systemthat is able to separate the three different views of data is likely to be flexible and adaptable. Thisflexibility and adaptability is data independence

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Physical Data Level

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The physical schema describes details of how data isstored: files, indices, etc. on the random access disksystem. It also typically describes the record layout of files and type of files (hash, b-tree, flat).

Early applications worked at this level - explicitly dealtwith details. E.g., minimizing physical distancesbetween related data and organizing the datastructures within the file (blocked records, linked lists of blocks, etc.)

Conceptual Data Level

This level describes the organizational data which isactually to be stored in the database. This levelcontains information about entire database in terms of a small number of relatively simple structures

Hides details of the physical level.

In the relational model, the conceptual schemapresents data as a set of tables.

The DBMS maps data access between the conceptual tophysical schemas automatically.

Physical schema can be changed without changingapplication:

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DBMS must change mapping from conceptual tophysical.

Referred to as physical data independence .

External Data Level This is the abstraction for a user. This level of abstraction generally describes only some small part of the database.

In the relational model, the external schema also

presents data as a set of relations. An external schemaspecifies a view of the data in terms of the conceptuallevel. It is tailored to the needs of a particular categoryof users. Portions of stored data should not be seen bysome users and begins to implement a level of securityand simplifies the view for these users

Examples:

Students should not see faculty salaries. Faculty should not see billing or payment data.

Information that can be derived from stored data might

be viewed as if it were stored. GPA not stored, calculated when needed.

Prospective Employers view Departments View

Student Name Enrolment Number

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Telephone Number

Student Name

HighestQualification

Address

ProfessionalSkill

Telephone Number


Logical View

Enrolment Number

Key: Numeric

Student Name String

Address String

City String

Pin code Numeric

Telephone Number

Numeric


String

ProfessionalSkill

String

Conceptual View

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Enrolment Number

9 digit number representation at offset 0

Student Name 25 character string at offset9

Address 30 character string at offset34

City 20 character string at offset64

Pincode .

Telephone Number

.


.

Professional

Skill

..

Internal View

The three views of data

COMPONENTS OF DBMS:-(1) DATA(2) HARDWARE(3) SOFTWARE(4) USER

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1: M

M:M

Entity Relationship Models:- (E-R models)

Entity set -- Rectangles

Properties/Attributes --Ellipes

Relationship --Diamonds

Links -- Lines

Example :-

Employee set Attributes Value

Employee E_name RajE_add SadarE_skill Cook

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Universitstudents

Stream

Marketing

Finance

HR

University


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Advantages of DBMS:-(1) Controlled redundancy(2) Reduced inconsistency(3) Data independence(4) Concurrent access(5) Data integrity(6) Data security(7) Backup & recovery(8) Easy accessing of data(9) Daat isolation(10) Speed, accuracy(11) Compactmess(12) Less work load

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Employee DepartmentsWork s For

name

add

skill

HR

financemarketing


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in certain types of projects and have skills centeredaround their expertise, whether that be software design , user research, web design , or industrial design .

Classification of users:-(1) Developers Versus NonDevelopers(2) Novices Vs Expert(3) Occasional Vs Frequent User

(4) Primary Vs Secondary

User Interface Design Principles

1. The structure principle . Your design shouldorganize the user interface purposefully, in

meaningful and useful ways based on clear,consistent models that are apparent andrecognizable to users, putting related thingstogether and separating unrelated things,differentiating dissimilar things and making similarthings resemble one another. The structure

principle is concerned with your overall userinterface architecture.

2. The simplicity principle . Your design shouldmake simple, common tasks simple to do,communicating clearly and simply in the users ownlanguage, and providing good shortcuts that are

meaningfully related to longer procedures.

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3. The visibility principle . Your design should keepall needed options and materials for a given taskvisible without distracting the user with extraneousor redundant information. Good designs dontoverwhelm users with too many alternatives orconfuse them with unneeded information.

4. The feedback principle . Your design should keepusers informed of actions or interpretations,changes of state or condition, and errors orexceptions that are relevant and of interest to theuser through clear, concise, and unambiguouslanguage familiar to users.

5. The tolerance principle . Your design should beflexible and tolerant, reducing the cost of mistakesand misuse by allowing undoing and redoing, whilealso preventing errors wherever possible bytolerating varied inputs and sequences and byinterpreting all reasonable actions reasonable.

6. The reuse principle . Your design should reuseinternal and external components and behaviors,maintaining consistency with purpose rather thanmerely arbitrary consistency, thus reducing theneed for users to rethink and remember.

Point To Be Considered At Preparing User InterfaceDesign:-

1) Screen Design2) Feedback & Observation3) Error Control

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4) Response Time5) Workstation Design6) Interactive User Dialogue7) Command Language8) Result9) Form, Icons, Graph, Color

An ideal interface design must contain:-1) consistency2) flexibility3) user control

Development Implementation Plan:-

The Development Implementation Plan describes howthe information system will be deployed, installed andtransitioned into an operational system. The plancontains an overview of the system, a brief descriptionof the major tasks involved in the implementation, the

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overall resources needed to support theimplementation effort (such as hardware, software.facilities, materials, and personnel), and any site-specific implementation requirements. The plan isdeveloped during the Design Phase and is updatedduring the Development Phase; the final version isprovided in the Integration and Test Phase and is usedfor guidance during the Implementation Phase. Theoutline shows the structure of the Implementation Plan.

Development Implementation Plan has following 3stages:-

1) Definition stage2) Development Stage3) Installation & Operation Stage

Definition stage:-a.Proposal Definitionb.Feasibility Study

(Technical Feasibility, Economical Feasibility& Behavioral Feasibility)c. Information Requirement Analysisd.Conceptual Design

Development Stage:-a.Physical System Designb.Physical Database Designc.Programme Developmentd.Procedure Development

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Installation & Operation Stage:-a.Conversionb.Operation & Maintenancec.Post Audit

Definition stage

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Feasibility study

Information requirementanalysis

Conceptual design

CANCELLATI

ON POSSIBILITY

AN

ANY

STAGE


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Development Stage

Installation & Operation Stage

Developing software and information systems involves a numberof processes:

consulting users to define what the software orsystem must be able to do

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Proposed definition

Physical system design

Physical database design

Programme development

Procedure development

Conversion

Operation & maintenance

Post audit/ feedback


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analyzing requirements and designing software andsystems to meet those requirements

developing, testing and implementing software andsystems (and redeveloping and retesting untilsoftware and systems meet specified requirements)

Evaluating and maintaining software and systemsto ensure that they meet customer requirementsand specifications.

developing quality standards and validationtechniques

auditing software and systems to ensurespecifications are accurate

researching, developing, implementing anddocumenting test plans and test scripts

evaluating automated testing tools Making recommendations about ways to improve

software and system quality.

Quality Assurance & Evaluation of InformationSystem:-Information systems quality assurance analysts develop andimplement policies and procedures to ensure customer satisfaction,maximum performance and overall quality of software products and

information systems.

The concept of quality in information system:-1) complete data2) accurate data3) understand output4) precise data

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5) timely output6) relevant output7) integrated output8) user friendly integration9) error control10) authorized user

Factors on the basis of which quality of anMIS is Judged:-

1) Correctness 2) Reliability3) Efficiency 4) Usability5) Maintainability 6) Portability7) Accuracy 8) Error Tolerance9) Expandability 10) Access Control &Audit11) Communicativeness

Organizational Duties Regarding QualityAssurance:-

TOPMANAGEMENT

INFORMATIONSYSTEM MGMT. USER

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establish overallorganization structureselect information system& executionapprove plan & budgetevaluate performanceapprove major h/w & s/w

supervision of qualityassurance proceduresupervision of informationsystem control procedureestablish & monitor

procedures to measure &report evidence of quality ,errors, applicationrepair maintenance

Database Development &maintenance

participation in input &output


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CONDITION FOR QUALITY ASSURENCE:1) organizational commitment2) internal problem division with respect to

operation3) to achieve user control in application design

Evaluation of information system:-1) significant task relevance2) willingness to pay3) system usage4) user interface satisfaction

Types of evaluation:-1) technical evaluation2) operational evaluation3) economic evaluation4) evaluation by use of performance monitor5) evaluation by uses of system logs &observation6) evaluation of proposed hardware, software7) evaluation of existing hardware, software

Mis_notes 4 Th n 5th Unit

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