CSC1100 - Chapter10 - Information System

Discovering Computers 2008

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Chapter 10 Chapter 10 Chapter 10 Chapter 10

Information System Information System Information System Information System

DevelopmentDevelopmentDevelopmentDevelopment

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Chapter 12 ObjectivesChapter 12 ObjectivesChapter 12 ObjectivesChapter 12 Objectives

List the phases in the system development cycleList the phases in the system development cycle

Identify the guidelines for system developmentIdentify the guidelines for system development

Discuss the importance of project management, feasibility assessment, documentation, and data and

information gathering techniques

Discuss the importance of project management, feasibility assessment, documentation, and data and

information gathering techniques

Describe the various tools used in object modelingDescribe the various tools used in object modeling

Explain the activities performed in the design phaseExplain the activities performed in the design phase

Recognize the develop programs activity is part of Recognize the develop programs activity is part of information gathering techniquesinformation gathering techniques

Explain the activities performed in the planning phase

Explain the activities performed in the planning phase

Discuss the purpose of the activities performed in the analysis phase

Discuss the purpose of the activities performed in the analysis phase

Describe the various tools used in process modelingDescribe the various tools used in process modeling

Recognize the develop programs activity is part of the system development cycle

Recognize the develop programs activity is part of the system development cycle

Discuss the activities performed in the implementation phase

Discuss the activities performed in the implementation phase

Discuss the purpose of the activities performedin the operation, support, and security phase

Discuss the purpose of the activities performedin the operation, support, and security phase

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What is the System Development Cycle?What is the System Development Cycle?What is the System Development Cycle?What is the System Development Cycle?

What is an information system (IS)?

Hardware, software, data, people, and

proceduresthat work

Hardware, software, data, people, and

proceduresthat work

System—Set of components that interact to achieve common goal

System—Set of components that interact to achieve common goalproceduresthat work

together to produce quality information

proceduresthat work together to produce quality information

to achieve common goalto achieve common goal

Businesses use many types of systems

Businesses use many types of systems

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The System Development Life CycleThe System Development Life CycleThe System Development Life CycleThe System Development Life Cycle

What are the phases of the system development cycle?

Phase 1. Planning

Phase 2. Analysis

Phase 3. Design� Review project

requests

� Prioritize project requests

� Conduct preliminary investigation

� Perform detailed analysis activities:

Study current system

Determine user requirements

� Acquire hardware and software, if necessary

Phase 4. Implementation

Phase 5. Operating, Support, and Security

requests

� Allocate resources

� Form project development team

Recommend solutionnecessary

� Develop details of system

� Develop programs, if necessary

� Install and test new system

� Train users

� Convert to new system

� Perform maintenanceactivities

� Monitor system performance

� Assess system security

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Arrange tasks into phases (groups of activities)


What are guidelines for system development?

Involve users(anyone for whom Involve users(anyone for whom system is being built)

Develop clearly defined standards(procedures company expects employees to follow)

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Who participates in the system development life cycle?

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Responsible for designing Responsible for designing and developing and developing

information systeminformation system

SA is the contact SA is the contact between users between users

and IT and IT professionalsprofessionals

SYSTEMS ANALYST

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What is theproject team?

Formed to work on project from beginning to end

Consists of users, systems analyst, and other IT professionals

Project leader—one member of the team who manages and controls project budget and

schedule

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What is project management?� Process of planning, scheduling, and controlling

activities during system development cycle� Project leaderidentifies elements for project

Goal, objectives, and Goal, objectives, and expectations, expectations,

Goal, objectives, and Goal, objectives, and expectations, expectations, TimeTime estimates for estimates for TimeTime estimates for estimates for

Required activitiesRequired activitiesRequired activitiesRequired activitiesexpectations, expectations,

collectively called collectively called scopescope

expectations, expectations, collectively called collectively called

scopescope

TimeTime estimates for estimates for each activityeach activity

TimeTime estimates for estimates for each activityeach activity

CostCost estimates for estimates for each activityeach activity

CostCost estimates for estimates for each activityeach activity

Activities that can Activities that can take place at same take place at same

timetime

Activities that can Activities that can take place at same take place at same

timetimeOrder of activitiesOrder of activitiesOrder of activitiesOrder of activities

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What is a Gantt chart?� Popular tool used to plan and schedulelarge, complex

projects

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What is project management software?� Program used by project leaders to plan, schedule, and

control development projects

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What is feasibility?

Measure of how suitable system developmentwill be to the

Operationalfeasibility

FOUR (4) feasibility

tests:will be to the

company Schedulefeasibility

tests:

Technicalfeasibility

Economicfeasibility

(also called cost/benefit feasibility)

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What is documentation?

Collection and summarization of data and information

Includes reports, diagrams, programs, and other deliverables

Project notebook contains all documentation for single project

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What are SIX (6) data and information gathering techniques?

� Review documentation� Observe� Questionnaire

Interview� Interview� Joint-application

design (JAD) session� Research

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What Initiates the System Development Cycle?What Initiates the System Development Cycle?What Initiates the System Development Cycle?What Initiates the System Development Cycle?

What are some reasons to create or modify an information system?

To improve existing system

To correct problem in existing system

Competition can lead to change

existing system

Outside group may mandate change

in existing system

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What Initiates the System Development Cycle?What Initiates the System Development Cycle?What Initiates the System Development Cycle?What Initiates the System Development Cycle?

What is a request for system services?� Formal request for

new or modified information system� Also called

project requestproject request

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Planning PhasePlanning PhasePlanning PhasePlanning Phase

What is the planning phase?

Begins when steering committee receives project request

Steering Steering committeecommittee——

decisiondecision--making making body for the body for the body for the body for the

companycompany

Function of committee:

Review and Review and approve project approve project

requestsrequests

Allocate Allocate resourcesresources

Form project Form project development development team for each team for each

approved approved projectproject

Prioritize Prioritize project requestsproject requests

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Analysis PhaseAnalysis PhaseAnalysis PhaseAnalysis Phase

What is the analysis phase?

Conduct preliminary Conduct preliminary investigation, also investigation, also

called feasibility called feasibility studystudy

Perform detailed Perform detailed analysisanalysis

studystudy

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What is the preliminary investigation?� Determine exact nature of problem or improvement

and whether it is worth pursuing� Findings are presented in feasibility report, also known as a feasibility study

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What is detailed analysis?

2. Determine user’s wants, needs,

1. Study how current system works

Sometimes called logical design

2. Determine user’s wants, needs, and requirements

3. Recommend solution

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What is process modeling?

Technique that describes processes that Technique that describes processes that transform inputs into outputstransform inputs into outputs

Also called structured analysis and designAlso called structured analysis and design

Technique that describes processes that Technique that describes processes that transform inputs into outputstransform inputs into outputs

Also called structured analysis and designAlso called structured analysis and design

Three tools used for process modelingThree tools used for process modelingThree tools used for process modelingThree tools used for process modeling

EntityEntity--relationship diagramsrelationship diagramsEntityEntity--relationship diagramsrelationship diagrams

Data flow diagramsData flow diagramsData flow diagramsData flow diagrams

Project dictionaryProject dictionaryProject dictionaryProject dictionary

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What is an entity-relationship diagram (ERD)?� Tool that graphically shows connections among entities

in system

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What is a data flow diagram (DFD)?� Tool that graphically shows flow of data in system

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What is a project dictionary?

Variety of techniques to enter items in

project dictionary

Helps keep track of huge amount

of details in system

Contains all the documentation and deliverables

of project

Data dictionary

Decision trees

Decision tables

Structured English

project dictionarysystemof project

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What is Structured English?� Used to explain details of process

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What is a decision table?� Lists variety of conditions and actions that correspond

to each condition

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What is a decision tree?� Shows conditions and actions graphically

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What is a data dictionary?� Stores name,

description, and other details about each data itemitem

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What is object modeling?

Combines data with the processes that act

on data into single unit called an objectobject

Object—an item that can contain both data and

procedures that read or manipulate the data

Sometimes called object-oriented (OO) analysis and design

Uses Unified Unified Modeling Language Modeling Language

(UML)(UML) —graphical tool for documenting system

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What is a use case diagram?� Graphically shows how actors

interact with information system� Actor—user or

other entity

� Use case—� Use case—function that actor can perform

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What is a class diagram?� Graphically shows classes and subclasses in system

� Class is group of objects—Can have lower levels called subclasses

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What is the system proposal? Assesses Assesses

feasibility feasibility of each of each

alternative alternative solutionsolution

Presented to Presented to steering steering

committee, committee, which decides which decides

how system will how system will be developedbe developed

Recommends Recommends the most the most feasible feasible

solution for solution for the projectthe project

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What are possible solutions?

Buy packaged software—prewritten software available for purchase

Buy packaged software—prewritten software available for purchase

Write own custom software—software Write own custom software—software

Vertical market Vertical market softwaresoftware—designed

for particular industry

Vertical market Vertical market softwaresoftware—designed

for particular industry

Horizontal market Horizontal market softwaresoftware—meets

needs of many companies

Horizontal market Horizontal market softwaresoftware—meets

needs of many companies

Outsource—have outside source develop software

Outsource—have outside source develop software

Write own custom software—software developed at user’s request

Write own custom software—software developed at user’s request

for particular industryfor particular industry

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Design PhaseDesign PhaseDesign PhaseDesign Phase

What is the design phase?

Acquire hardware and softwareAcquire hardware and software

Develop all details of new or modified information systemDevelop all details of new or modified information system

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What is a detailed design?

Detailed design specifications for components in proposed solution

Sometimes calledphysical design

Sometimes calledphysical design

Includes several activities

Database design

Database design

Input and output design

Input and output design

Program design

Program design

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What is needed to acquire new hardware and software?

� Identify all hardware and software requirements of new or modified system

Solicit vendor Solicit vendor proposalsproposals

Solicit vendor Solicit vendor proposalsproposals

Identify technicalIdentify technicalspecificationsspecifications

Identify technicalIdentify technicalspecificationsspecifications

Test and evaluate Test and evaluate vendor proposalsvendor proposalsTest and evaluate Test and evaluate vendor proposalsvendor proposals

proposalsproposalsproposalsproposals

Make a decisionMake a decisionMake a decisionMake a decision

specificationsspecificationsspecificationsspecifications

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What are three basic documents used to summarize technical specifications?

Vendor quotes price(s) for

listed product(s)

Identifies product(s) you want

Request for quotation (RFQ)Request for quotation (RFQ)

p. 639 Next

Less formal method that uses standard

form to request information about product or service

Vendor selects product(s) that meet(s) your

requirements and then quotes

price(s)

Request for information (RFI)Request for information (RFI)

Request for proposal (RFP)Request for proposal (RFP)

Click to view Web Link, click Chapter 12, Click Web Link from left navigation, then click Request for Proposalsbelow Chapter 12

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What is a turnkey solution?

� Complete system provided by value-added reseller� Value-added reseller

(VAR) purchases products from manufacturer and then resells them, offering additional services with

p. 639 Fig. 12-18 Next

additional services with product

� Authorized VARs must meet certain manufacturer-specified requirements

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Design PhaseDesign PhaseDesign PhaseDesign PhaseHow do systems analysts test software products?

� References from vendor� Talk to current users of product� Product demonstrations� Trial version of software� Benchmark test

p. 640 Fig. 12-19 Next

� Benchmark testmeasures performance

Click to view Web Link, click Chapter 12, Click Web Link from left navigation, then click Benchmark Testsbelow Chapter 12

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What is a mockup?� Sample of input or output that contains actual data

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What is a layout chart?

� Input or output that contains programming-like notations for data items

p. 641 Fig. 12-21 Next

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What is an inspection?

Used to review detailed design specifications before they are given to programming team

Step-by-step review by project team and users

of any system development cycle deliverable

p. 643 Next

Used throughout entire system development

cycle to review a variety of deliverables

to programming team

Identifies any errors and allows IT personnel

to correct them

cycle deliverable

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What is a prototype?

Working model of proposed system

Working model of proposed system

Beginning a prototype too early may lead to

problems

Beginning a prototype too early may lead to

problems

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What is computer-aided software engineering (CASE)?� Software tools designed to support activities of system

development cycle

Graphics—Enables drawing of diagrams

Prototyping—Creates models of proposed system

Project repository—Stores diagrams, specifications,

descriptions, programs, and other deliverables

Housekeeping—Establishes user accounts and provides

backup and recovery functions

Quality assurance—Analyzes deliverables for accuracy

Code generators—Create actual computer programs from design specifications

other deliverables

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What is integrated computer-aided software engineering (I-CASE)?� Integrated case products

p. 642 - 643 Fig. 12-22 Next

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Convert to new systemConvert to new system

Implementation PhaseImplementation PhaseImplementation PhaseImplementation Phase

What is the implementation phase?� Purpose is to construct, or build, new or modified

system and then deliver it to users

Train usersTrain usersTrain usersTrain users

Install and test new systemInstall and test new system

Develop programsDevelop programs

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What is the program development cycle?� Programmers write

programs from specifications

� Follows six steps Documentsolution

Design solution

Analyze requirements

Test solution

Implement design

Validate design

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What are the four types of tests performed by system developers?

Systems testUnit Test

Verifies each individual program

Verifies all programs in application work

Verifies application works with other

applications

Integration Test

individual program works by itself

in application work together

Verifies the new system works with

actual data

Acceptance Test

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What is training ?� Showing users exactly

how they will use new hardware and software in system

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What are conversion strategies?� Used to change from old system to new system

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Operation, Support, and Security PhaseOperation, Support, and Security PhaseOperation, Support, and Security PhaseOperation, Support, and Security Phase

What is the operation, support, and security phase phase?

Conduct post-implementation system review—meeting to find out if information system is performing according to expectations

Perform Maintenance Activities

� Provides ongoing assistance after system is implemented

Perform Maintenance Activities

Monitor System Performance

Assess System Security

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Operation, Support, and Security PhaseOperation, Support, and Security PhaseOperation, Support, and Security PhaseOperation, Support, and Security Phase

What is a computer security plan?

� Summarizes in writing all of the safeguards that are in place to protect a company’s information assets

For each risk,For each risk,identify theidentify the

Identify allIdentify all

p. 646 Next

identify theidentify thesafeguards safeguards

that exist that exist to detect, to detect,

prevent, and prevent, and recover from a lossrecover from a loss

Identify allIdentify allsecurity riskssecurity risks

that may that may cause ancause an

informationinformationlossloss

Identify allIdentify allinformation information assets of an assets of an organizationorganization

Click to view Web Link, click Chapter 12, Click Web Link from left navigation, then click ICSA below Chapter 12

Click to view Web Link, click Chapter 12, Click Web Link from left navigation, then click Computer Security Planbelow Chapter 12

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Summary of Information System DevelopmentSummary of Information System DevelopmentSummary of Information System DevelopmentSummary of Information System Development

Phases in the system development cycle

Phases in the system development cycle

Activities that occur during the entire system development cycleActivities that occur during the entire system development cycle

Guidelines for system developmentGuidelines for system development

entire system development cycleentire system development cycle

Chapter 9 Complete

CSC1100 - Chapter10 - Information System

Technology

Transcript of CSC1100 - Chapter10 - Information System