Building and Managing Building and Managing SystemsSystems

Chapter Thirteen (10E)Chapter Thirteen (10E)

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Overview of Systems DevelopmentOverview of Systems Development

Systems development - activities that go Systems development - activities that go into producing an information systems into producing an information systems solution to an organization problem or solution to an organization problem or opportunityopportunity– structured type of problem solving with structured type of problem solving with

distinct activitiesdistinct activities These activities are present to some extent These activities are present to some extent

for all of the different ways of developing for all of the different ways of developing systems described latersystems described later

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System Development ProcessSystem Development Process

Systems analysisSystems analysis System designSystem design ProgrammingProgramming TestingTesting ConversionConversion Production & maintenanceProduction & maintenance

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Phases of the Systems DevelopmentPhases of the Systems Development

Analysis Analysis DesignDesign Programming Programming & Testing & Testing

ConversioConversionn

Prod&Prod&

MaintenanceMaintenance

InvestigatioInvestigationn

RequiremeRequirements to nts to componentcomponentss

Training Training

FeasibilityFeasibility

Evaluate Evaluate

alternativealternativess ConversionConversion

RequiremenRequirementsts

definition definition

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Systems AnalysisSystems Analysis Definition - analysis of problem to be solved with Definition - analysis of problem to be solved with

an information systeman information system Major tasksMajor tasks

– Understand the problem Understand the problem Define the problemDefine the problem Identify causesIdentify causes Specify solutions Specify solutions

– Feasibility study: can problem be solved within Feasibility study: can problem be solved within constraints?constraints?

– Establishing information requirements for end Establishing information requirements for end usersusers

Deliverables include system proposal, feasibility Deliverables include system proposal, feasibility study, user requirementsstudy, user requirements

Approval by management to proceedApproval by management to proceed Role of the end userRole of the end user

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FeasibilityFeasibility

TechnicalTechnical: assess hardware, software, : assess hardware, software, technical resourcestechnical resources

EconomicEconomic: will benefits outweigh costs: will benefits outweigh costs OperationalOperational: Is solution desirable within : Is solution desirable within

existing conditions?existing conditions?

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Systems DesignSystems Design

Definition - details how a system will meet Definition - details how a system will meet the information requirements determined the information requirements determined by systems analysisby systems analysis

Designer responsibilitiesDesigner responsibilities– consider alternate technologiesconsider alternate technologies– manage and control the technical manage and control the technical

realization of the systemrealization of the system– Translate the system requirements into Translate the system requirements into

specifications that will deliver a system specifications that will deliver a system that solves the problems determined in that solves the problems determined in systemssystems analysisanalysis

Role of end users in systems designRole of end users in systems design

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Examples of Translation of Requirements Examples of Translation of Requirements into Specifications in the Design Phaseinto Specifications in the Design Phase

Design of input files (usually database tables)Design of input files (usually database tables) Procedures (the formulas or algorithms that will Procedures (the formulas or algorithms that will

be used to process the inputs into outputs)be used to process the inputs into outputs) Output files (the files that will contain the Output files (the files that will contain the

processed data, or the files that record input processed data, or the files that record input from customers, employees, suppliers, etc.)from customers, employees, suppliers, etc.)

User interface (the design of windows, menus, User interface (the design of windows, menus, icons, drop down lists, etc.)icons, drop down lists, etc.)

Interfaces (determination of how the system Interfaces (determination of how the system will interact with other systems; inputs from will interact with other systems; inputs from other systems, outputs to other systems)other systems, outputs to other systems)

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Additional Design SpecificationsAdditional Design Specifications

OUTPUTOUTPUT– MEDIUM; CONTENT; TIMINGMEDIUM; CONTENT; TIMING

INPUTINPUT– ORIGINS; FLOW; DATA ENTRYORIGINS; FLOW; DATA ENTRY

USER INTERFACEUSER INTERFACE– SIMPLICITY; EFFICIENCY; LOGICSIMPLICITY; EFFICIENCY; LOGIC– FEEDBACK; ERRORSFEEDBACK; ERRORS

DATABASE DESIGNDATABASE DESIGN– LOGICAL DATA RELATIONSLOGICAL DATA RELATIONS– VOLUME, SPEED REQUIREMENTSVOLUME, SPEED REQUIREMENTS– FILE ORGANIZATION & DESIGNFILE ORGANIZATION & DESIGN– RECORD SPECIFICATIONSRECORD SPECIFICATIONS

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Designer SpecificationsDesigner Specifications

PROCESSINGPROCESSING– COMPUTATIONSCOMPUTATIONS– PROGRAM MODULESPROGRAM MODULES– REQUIRED REPORTSREQUIRED REPORTS– TIMING OF OUTPUTSTIMING OF OUTPUTS

MANUAL PROCEDURESMANUAL PROCEDURES– WHAT ACTIVITIESWHAT ACTIVITIES– WHO PERFORMS THEMWHO PERFORMS THEM– WHO PERFORMS THEMWHO PERFORMS THEM– HOWHOW– WHEREWHERE

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Designer SpecificationsDesigner Specifications

CONVERSIONCONVERSION– TRANSFER FILESTRANSFER FILES– INITIATE NEW PROCEDURESINITIATE NEW PROCEDURES– SELECT TESTING MODULESSELECT TESTING MODULES– CUT OVER TO NEW SYSTEMCUT OVER TO NEW SYSTEM

TRAININGTRAINING– SELECT TRAINING TECHNIQUESSELECT TRAINING TECHNIQUES– DEVELOP TRAINING MODULESDEVELOP TRAINING MODULES– IDENTIFY TRAINING FACILITIESIDENTIFY TRAINING FACILITIES

ORGANIZATIONAL CHANGESORGANIZATIONAL CHANGES– TASK REDESIGNTASK REDESIGN– JOB DESIGNJOB DESIGN– PROCESS DESIGNPROCESS DESIGN– OFFICE / ORGANIZATION STRUCTURE DESIGNOFFICE / ORGANIZATION STRUCTURE DESIGN– REPORTING RELATIONSHIPSREPORTING RELATIONSHIPS

**

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Role Of End Users in Analysis and Role Of End Users in Analysis and DesignDesign

Users drive systems effortUsers drive systems effort Must have sufficient control to ensure Must have sufficient control to ensure

system reflects business priorities and system reflects business priorities and needsneeds

Functional users drive system information Functional users drive system information requirementsrequirements

Users can play an important role in the Users can play an important role in the design effort (see preceding slides)design effort (see preceding slides)

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Completing System Development Completing System Development ProcessProcess

Programming: Translating needs to Program Programming: Translating needs to Program CodeCode

Testing: Does System Produce Desired Testing: Does System Produce Desired Results?Results?– Unit testingUnit testing: Tests Each Unit Separately: Tests Each Unit Separately– System testingSystem testing: Do Modules Function as : Do Modules Function as

planned?planned?– Acceptance testingAcceptance testing: Final Certification: Final Certification– Test planTest plan: Preparations for Tests to be : Preparations for Tests to be

PerformedPerformed Role of the end user in testingRole of the end user in testing

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ConversionConversion

Strategies for conversionStrategies for conversion– ParalleParallell: Old & New Run Same : Old & New Run Same

Problems. Give Same Results?Problems. Give Same Results?– DirectDirect: Risky Conversion to New : Risky Conversion to New

SystemSystem– PilotPilot: Introduce Into One Area. Does it : Introduce Into One Area. Does it

Work? Yes: Introduce into Other AreaWork? Yes: Introduce into Other Area– PhasedPhased: Introduce in Stages: Introduce in Stages

Training and Documentation Training and Documentation Role of end users in conversionRole of end users in conversion

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Production & MaintenanceProduction & Maintenance

Production: Constant Review by Users & Production: Constant Review by Users & Operators. Does the system meet its goals?Operators. Does the system meet its goals?

Maintenance: Upkeep; Update; Corrections Maintenance: Upkeep; Update; Corrections Over TimeOver Time– Fix problems not discovered during Fix problems not discovered during

earlier stagesearlier stages– Make changes to the system dictated by Make changes to the system dictated by

new requirementsnew requirements

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SYSTEMS DEVELOPMENTSYSTEMS DEVELOPMENT

CORE ACTIVITYCORE ACTIVITY DESCRIPTIONDESCRIPTION

SYSTEMS ANALYSIS IDENTIFY PROBLEM(S) SPECIFY PROBLEM ESTABLISH INFORMATION REQUIREMENTS

SYSTEMS DESIGN CREATE LOGICAL DESIGN SPECIFICATIONS CREATE PHYSICAL DESIGN SPECIFICATIONS MANAGE TECHNICAL REALIZATION OF SYSTEM

PROGRAMMING TRANSLATE DESIGN INTO CODE

TESTING UNIT SYSTEMS ACCEPTANCE

CONVERSION PLAN PREPARE DOCUMENTATION TRAIN USERS & TECHNICAL STAFF

PRODUCTION & MAINTENANCE

OPERATE EVALUATE MODIFY

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Five Methods to Build SystemsFive Methods to Build Systems

Five methodsFive methods– Systems Life CycleSystems Life Cycle– PrototypingPrototyping– Application SoftwareApplication Software– End-user DevelopmentEnd-user Development– OutsourcingOutsourcing

Each method has the six general steps Each method has the six general steps described in the systems development described in the systems development processprocess

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Stages of the Systems Life CycleStages of the Systems Life Cycle

Oldest methodOldest method Stages correspond to the stages of systems Stages correspond to the stages of systems

development described earlierdevelopment described earlier Birth, maturity, death (the cycle repeats)Birth, maturity, death (the cycle repeats) Used for TPS, MIS, or large complex systemsUsed for TPS, MIS, or large complex systems Formal process, controls, deliverablesFormal process, controls, deliverables LimitationsLimitations

– Resource intensive (time and money)Resource intensive (time and money)– Inflexible and inhibits change (freezing of Inflexible and inhibits change (freezing of

specifications)specifications)– Ill-suited for decision-oriented Ill-suited for decision-oriented

applications or situations where system applications or situations where system requirements are vaguerequirements are vague

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PrototypingPrototyping

Definition - process of building an Definition - process of building an experimental system quickly and experimental system quickly and inexpensively for demonstration and inexpensively for demonstration and evaluation so that end users can better evaluation so that end users can better determine information requirementsdetermine information requirements

Iterative designIterative design Very informal compared to SLCVery informal compared to SLC

– requirements are determined requirements are determined dynamically instead of frozen in dynamically instead of frozen in advance advance

– No distinct phasesNo distinct phases– No distinct intermediate deliverables No distinct intermediate deliverables

for managementfor management

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Identifyuser

needs

Developa

prototype

Usethe

prototype

1.

2.

3.

4.

Y

NPrototypeacceptable

?

Development of a Prototype

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The Attraction of PrototypingThe Attraction of Prototyping

Prototyping is useful when user requirements Prototyping is useful when user requirements are uncertain, developing user interfaces, or are uncertain, developing user interfaces, or developing interactive applications with developing interactive applications with multiple screensmultiple screens

Communications between the systems analyst Communications between the systems analyst and user are improved.and user are improved.

The user plays a more active role in system The user plays a more active role in system development.development.

Implementation is much easier because the user Implementation is much easier because the user knows what to expect.knows what to expect.

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Potential Pitfalls of PrototypingPotential Pitfalls of Prototyping

The haste to deliver the prototype may produce The haste to deliver the prototype may produce shortcuts in problem definition, alternative shortcuts in problem definition, alternative evaluation, and documentation.evaluation, and documentation.

The users may get so excited about the The users may get so excited about the prototype that they have unrealistic prototype that they have unrealistic expectations of the operational system.expectations of the operational system.

The computer-human interface provided by The computer-human interface provided by certain prototyping tools may not reflect good certain prototyping tools may not reflect good design techniques.design techniques.

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Applications Software PackagesApplications Software Packages

Definition - set of programs that are Definition - set of programs that are available for sale or leaseavailable for sale or lease

Packages eliminate the need for writing Packages eliminate the need for writing programs when building systems; also programs when building systems; also reduces design, programming, testing, reduces design, programming, testing, conversion and maintenance workconversion and maintenance work

When are they appropriate?When are they appropriate?– common functionscommon functions– limited resources for in-house limited resources for in-house

developmentdevelopment– desktop applications for end usersdesktop applications for end users

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Types of Prepackaged SoftwareTypes of Prepackaged Software

Accounts payableAccounts payable Accounts Accounts

receivablereceivable Check processingCheck processing Document imagingDocument imaging Forecasting and Forecasting and

modelingmodeling General ledgerGeneral ledger Health insuranceHealth insurance Hotel managementHotel management Human resourcesHuman resources

Job accountingJob accounting Inventory controlInventory control Job costingJob costing Mailing labelsMailing labels Order entryOrder entry PayrollPayroll Process controlProcess control Route schedulingRoute scheduling Sales and Sales and

distributiondistribution Stock managementStock management Tax accountingTax accounting

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Advantages/Disadvantages of PackagesAdvantages/Disadvantages of Packages

AdvantagesAdvantages– Speed up of systems development phasesSpeed up of systems development phases– Periodic enhancements/updates from the Periodic enhancements/updates from the

vendor (reduced maintenance)vendor (reduced maintenance)– External work is often perceived as External work is often perceived as

superiorsuperior– Software costs appear to be fixedSoftware costs appear to be fixed

DisadvantagesDisadvantages– Packages never satisfy all user Packages never satisfy all user

requirements (70% is very good)requirements (70% is very good)– costs of customizationcosts of customization

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End-User DevelopmentEnd-User Development

Definition - the development of information Definition - the development of information systems by end users with little or no systems by end users with little or no

formal assistance from technical specialistsformal assistance from technical specialists End user tools - query languages, report End user tools - query languages, report

generators, graphics languages, generators, graphics languages, applications generators, or microcomputer applications generators, or microcomputer toolstools

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End-User DevelopmentEnd-User Development

Definition - the development of information Definition - the development of information systems by end users with little or no systems by end users with little or no

formal assistance from technical specialistsformal assistance from technical specialists End user tools - query languages, report End user tools - query languages, report

generators, graphics languages, generators, graphics languages, applications generators, or microcomputer applications generators, or microcomputer toolstools

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Historical Factors That Encouraged Historical Factors That Encouraged End User Application DevelopmentEnd User Application Development

The programming backlogThe programming backlog

The widespread use of PCsThe widespread use of PCs

The emergence of 4GLs (spreadsheets, The emergence of 4GLs (spreadsheets, query languages, and report generators)query languages, and report generators)

Increasing popularity of client/server Increasing popularity of client/server architecturearchitecture

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Typical End User ApplicationsTypical End User Applications

Use of Use of spreadsheetsspreadsheets

Management Management graphicsgraphics

Word processing Word processing (mail merge)(mail merge)

Queries and report Queries and report generationgeneration

Desktop publishingDesktop publishing EmailEmail

Creating local Creating local databasesdatabases

Using external Using external databasesdatabases

Calendaring, Calendaring, meeting meeting management, and management, and personal supportpersonal support

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Benefits and Risks of EUCBenefits and Risks of EUC

BenefitsBenefits– Quicker Quicker

developmentdevelopment– Good fit to needsGood fit to needs– Efficient Efficient

utilizationutilization– Acquisition of Acquisition of

skillsskills– Free IS staff timeFree IS staff time

RisksRisks– Poor Poor

documentationdocumentation– Lack of quality Lack of quality

assurance assurance standards and standards and controlscontrols

– Islands of Islands of informationinformation

– Duplication of Duplication of efforteffort

– Security problemsSecurity problems

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Outsourcing Information SystemsOutsourcing Information Systems

Definition - the practice of contracting Definition - the practice of contracting computer center operations, computer center operations, telecommunications networks, or telecommunications networks, or application development to external application development to external vendors. Older usage of this term meant vendors. Older usage of this term meant hiring an outside firm to develop a custom hiring an outside firm to develop a custom system. system.

Outsourcing is big business; IBM, AT&T, Outsourcing is big business; IBM, AT&T, EDS, big accounting firms are all major EDS, big accounting firms are all major outsourcersoutsourcers

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Newer MethodologiesNewer Methodologies Newer methodologiesNewer methodologies

– Joint application development (JAD)Joint application development (JAD)– Rapid application development (RAD)Rapid application development (RAD)

CharacteristicsCharacteristics– Attempts to speed development by reducing Attempts to speed development by reducing

documentation involved in SDLCdocumentation involved in SDLC– Large amounts of prototypingLarge amounts of prototyping– Heavy involvement of end users throughout Heavy involvement of end users throughout

projectproject– End users often take leadership roles End users often take leadership roles – Does not skip analysis stage like prototypingDoes not skip analysis stage like prototyping– Lots of team meetings where users and IS Lots of team meetings where users and IS

professionals work togetherprofessionals work together– Use of many new tools (e.g., Visual Basic, Java, Use of many new tools (e.g., Visual Basic, Java,

C#, collaborative software, reusable software)C#, collaborative software, reusable software)