lecture 7 software development

Systems Systems DevelopmentDevelopment

Systems DevelopmentSystems Development

• It refers to all activities that go into It refers to all activities that go into producing an information systems producing an information systems solution to an organizational solution to an organizational problem or opportunityproblem or opportunity

Systems DevelopmentSystems Development• IS/IT projects are generally risky or tend to fail IS/IT projects are generally risky or tend to fail

because ofbecause of– High rate of technology changesHigh rate of technology changes– High tendency for users to change requirementsHigh tendency for users to change requirements– Misunderstanding of IS/IT deliverables and Misunderstanding of IS/IT deliverables and

business outcomesbusiness outcomes– Requirements determination tends to be dodgyRequirements determination tends to be dodgy– Change associated with IS/IT projects are complexChange associated with IS/IT projects are complex

• IS potentially change an organization’s IS potentially change an organization’s structure, culture, politics and workstructure, culture, politics and work

– Most common reason for failure of large projects is Most common reason for failure of large projects is due to organizational and political resistance to due to organizational and political resistance to change. This is because they influence access to a change. This is because they influence access to a key resourcekey resource

Justification of IS/IT Justification of IS/IT ProjectsProjects

• Justifying IS/IT projects involvesJustifying IS/IT projects involves– Matching the costs with benefitsMatching the costs with benefits– Identifying risks and plan to manage itIdentifying risks and plan to manage it

Categories of Cost of a new Categories of Cost of a new systemsystem

CostCost ExampleExample

Equipment CostEquipment Cost • Computer and Computer and peripheralsperipherals

• Ancillary equipmentAncillary equipment• The initial system The initial system

Supplies (disk, tapes, Supplies (disk, tapes, paper etc)paper etc)

Installation CostInstallation Cost •New buildings (if New buildings (if necessary)necessary)•The computer roomThe computer room


Development CostsDevelopment Costs •Cost measuring and Cost measuring and Analyzing the existing Analyzing the existing systemsystem•Cost of looking at the Cost of looking at the new system – new system –

–software/ consultancy software/ consultancy workwork–System analysisSystem analysis–ProgrammingProgramming–Change over costChange over cost

•File conversionFile conversion


Personnel CostPersonnel Cost •Staff trainingStaff training•Staff recruitmentStaff recruitment•Staff salaries and Staff salaries and pensionpension•Redundancy Redundancy paymentspayments•OverheadsOverheads


Operational Operational CostsCosts

•Consumable materials Consumable materials (tapes, disks, stationery (tapes, disks, stationery etc)etc)•MaintenanceMaintenance•Accommodation costsAccommodation costs•Power/Insurance/Power/Insurance/telephonetelephone•Standby arrangements, Standby arrangements, in case the system breaks in case the system breaks downdown

Benefits of a Proposed Benefits of a Proposed SystemSystem

• Savings because the old system will no longer be Savings because the old system will no longer be operated.operated.– Savings may includeSavings may include

• Savings in staff costSavings in staff cost• Savings in other operational cost such as consumable materialsSavings in other operational cost such as consumable materials

• Extra savings or revenue benefits because of the Extra savings or revenue benefits because of the improvements or enhancements that the new system improvements or enhancements that the new system should bringshould bring– Possibly more sales revenue and so additional contributionPossibly more sales revenue and so additional contribution– Better stock control (with a new stock control system) and Better stock control (with a new stock control system) and

so fewer stock losses from obsolescence and deteriorationso fewer stock losses from obsolescence and deterioration– Further savings in staff time, resulting perhaps in reduced Further savings in staff time, resulting perhaps in reduced

future staff growthfuture staff growth

Benefits of a Proposed Benefits of a Proposed SystemSystem

• Possibly, some one-off revenue benefits Possibly, some one-off revenue benefits from the sale of equipment which the from the sale of equipment which the existing system uses, but which will no existing system uses, but which will no longer be requiredlonger be required

• Intangible benefitsIntangible benefits– Greater customer satisfactionGreater customer satisfaction– Improve staff morale from working with a Improve staff morale from working with a

better systembetter system– Better decision, making it hard to quantify, Better decision, making it hard to quantify,

but may result from better MIS, DSS or ESSbut may result from better MIS, DSS or ESS

IS/IT Project RisksIS/IT Project Risks

• Risk assessment involves the determination and Risk assessment involves the determination and evaluation of factors that are likely to hinder evaluation of factors that are likely to hinder the delivery of the projectthe delivery of the project

• Risks can be assessed by asking questions Risks can be assessed by asking questions about the project definition, scope and viabilityabout the project definition, scope and viability– What business need is the project going to meet?What business need is the project going to meet?– Has the need and requirement well understood?Has the need and requirement well understood?– Is the project feasible?Is the project feasible?– Have you determined the alternatives?Have you determined the alternatives?


– For each alternative have you assessedFor each alternative have you assessed• Operational feasibilityOperational feasibility

– Will it fit into the way things are done in the Will it fit into the way things are done in the organization?organization?

– Will it be accepted?Will it be accepted?– Will it be abused?Will it be abused?

• Technical feasibilityTechnical feasibility– Is it a proven technology?Is it a proven technology?– Is it compatible with the current systems?Is it compatible with the current systems?– Do we have the technical support capacity? If not Do we have the technical support capacity? If not

can we easily acquire it?can we easily acquire it?


• Financial feasibilityFinancial feasibility– Is the project financially sound?Is the project financially sound?

• Social feasibilitySocial feasibility– Will it adversely affect a section of the Will it adversely affect a section of the

communitycommunity– Will it create social disharmonyWill it create social disharmony– Will some people lose their jobs?Will some people lose their jobs?– Will it affect some people’s span of control in the Will it affect some people’s span of control in the

organization?organization?

• The assessment of technical feasibility is The assessment of technical feasibility is concerned with the technical performance concerned with the technical performance criteria the system will have to meet to be criteria the system will have to meet to be accepted. accepted.

• For example:For example:– The ability of the system to produce defined outputs The ability of the system to produce defined outputs

in a given time scale. For example, to produce in a given time scale. For example, to produce 120,000 examination certificates in two weeks.120,000 examination certificates in two weeks.

– The ability of the system to provide minimum The ability of the system to provide minimum response times under certain conditions. For response times under certain conditions. For example, no more than a two-second response time example, no more than a two-second response time when accessing student information.when accessing student information.

– The facility to input a large number of The facility to input a large number of documents in a given time scale. For documents in a given time scale. For example, to enter the results for example, to enter the results for 200,000 students in four weeks.200,000 students in four weeks.

– The facility to communicate data to The facility to communicate data to distant locations. For example, to distant locations. For example, to transfer examination results to a distant transfer examination results to a distant location.location.

– The facility to interface with other The facility to interface with other software already used by the software already used by the organisation. For example, to allow data organisation. For example, to allow data mining tools to be used on student mining tools to be used on student information.information.

• Technical issues might include:Technical issues might include:• (1) The technical issues concerning the (1) The technical issues concerning the

scanned input of hand-written scripts into scanned input of hand-written scripts into the computer system. Will it be possible to the computer system. Will it be possible to scan with sufficient quality to allow the scan with sufficient quality to allow the marker to read the script on the screen?marker to read the script on the screen?

• (2) If sufficient quality can be achieved in (2) If sufficient quality can be achieved in the scanning process, will it be possible to the scanning process, will it be possible to scan with sufficient speed at that quality scan with sufficient speed at that quality to meet the marking process deadline?to meet the marking process deadline?

• The technical issues concerning the The technical issues concerning the security of transfer of scripts security of transfer of scripts through the Internet and how the through the Internet and how the marker accesses the allocated marker accesses the allocated scripts from his or her computer. scripts from his or her computer. What equipment will the marker What equipment will the marker need for this on-line access? For need for this on-line access? For example, what size and quality of example, what size and quality of display unit will be required?display unit will be required?

Operational and Social Operational and Social FeasibilityFeasibility

• Operational and social feasibility is Operational and social feasibility is concerned with the organisational, social, concerned with the organisational, social, human and political impact of the system.human and political impact of the system.

• Amongst the issues considered are:Amongst the issues considered are:– Likely job changes caused by the system and Likely job changes caused by the system and

how these might affect the motivation of how these might affect the motivation of employees.employees.

– The disturbance of established organisational The disturbance of established organisational structures within the company and trading structures within the company and trading relationships with suppliers.relationships with suppliers.

– The expected skill requirements of The expected skill requirements of users of the system and the implication users of the system and the implication of bridging any gaps in those skills.of bridging any gaps in those skills.

– Any conflicts with how the organisation Any conflicts with how the organisation usually does business, the image it usually does business, the image it projects and the business ethics it projects and the business ethics it wishes to adhere to.wishes to adhere to.

Operational or social Operational or social feasibility issues might feasibility issues might

includeinclude• Health and safety issues arising from on-line Health and safety issues arising from on-line

marking. The markers could potentially spend a marking. The markers could potentially spend a long time looking at the screen and guidance long time looking at the screen and guidance will have to be given on equipment and work will have to be given on equipment and work practice.practice.

• The software skill levels of markers. Appropriate The software skill levels of markers. Appropriate training will have to be given in the software training will have to be given in the software application and supporting technology.application and supporting technology.

• The employment implications for staff at head The employment implications for staff at head office will also have to be considered. They have office will also have to be considered. They have less involvement in the proposed system and so less involvement in the proposed system and so redundancies may be possible.redundancies may be possible.

System Development System Development ProcessProcess• Information systems development projects begin with Information systems development projects begin with

some real or perceived needs some real or perceived needs The processThe process• Identify the problem or opportunity that we need to Identify the problem or opportunity that we need to

address( the purpose of the system)address( the purpose of the system)• Identify the detailed requirements for the new systemIdentify the detailed requirements for the new system• We identify the alternative ways to address the problem We identify the alternative ways to address the problem

(different design alternative) and select the best(different design alternative) and select the best• We design the new system in detailWe design the new system in detail• We develop the system (i.e. coding and testing – unit We develop the system (i.e. coding and testing – unit

testing, system testing and integration testing)testing, system testing and integration testing)• Implement the new system (i.e. install the system, train Implement the new system (i.e. install the system, train

users, conduct testing – unit testing, system testing, users, conduct testing – unit testing, system testing, integration testing and acceptance testing; and identify integration testing and acceptance testing; and identify appropriate changeover technique to adopt) and conduct appropriate changeover technique to adopt) and conduct file conversions (input/output files -- forms and reports, -- file conversions (input/output files -- forms and reports, -- menus, GUIs, etc). menus, GUIs, etc).

• Operate and maintainOperate and maintain

System Development Life System Development Life Cycle (SDLC)Cycle (SDLC)

• It is one formal process of developing It is one formal process of developing information information

• It is a series of recommended steps, or It is a series of recommended steps, or phases designed to reduce the risks of phases designed to reduce the risks of developing systemsdeveloping systems

• The actual number of steps and titles The actual number of steps and titles given to each step vary from organization given to each step vary from organization to organizationto organization

• A step/phase has to be completed (with A step/phase has to be completed (with all deliverables produced and accepted) all deliverables produced and accepted) before the next one is started.before the next one is started.

System Development Life System Development Life Cycle (SDLC)Cycle (SDLC)

Putting it together:Putting it together:• Software/systems development life cycle Software/systems development life cycle

is an information system development is an information system development methodology that partitions the systems methodology that partitions the systems development process into 6 stages/steps development process into 6 stages/steps that must be completed sequentially that must be completed sequentially with a formal division of labour between with a formal division of labour between end-users and information systems end-users and information systems specialists.specialists.

Phases of IS/IT projectsPhases of IS/IT projects

• SLDC involves the following 6 SLDC involves the following 6 steps/phases:steps/phases:

• 1. Requirements Definition1. Requirements Definition• 2. Systems Analysis2. Systems Analysis• 3. Systems Design3. Systems Design• 4. Systems Development/Acquisition4. Systems Development/Acquisition• 5. Installation & 5. Installation &

Deployment/ImplementationDeployment/Implementation• 6. Post-Implementation Review6. Post-Implementation Review

Stages/PhasesStages/Phases End productsEnd products• Project definitionProject definition Project proposal reportProject proposal report• Systems study/feasibility studySystems study/feasibility study System proposal System proposal

reportreport• Design Design Design specificationsDesign specifications• ProgrammingProgramming Program codeProgram code• Installation & Implementation Installation & Implementation System System

performance testsperformance tests• Post-implementation Post-implementation Post-implementation Post-implementation

audit reportaudit report

Phases of IS/IT projectsPhases of IS/IT projectsRequirements Definition PhaseRequirements Definition Phase• Identifies the need for the software Identifies the need for the software

projectproject• Defines the problem Defines the problem • Determines the objectives and scope for Determines the objectives and scope for

the projectthe project• Identifies the constraints regarding:Identifies the constraints regarding:

– FinanceFinance– Technical issuesTechnical issues– TimeTime– Procedures, etc.Procedures, etc.


Analysis PhaseAnalysis Phase• Detailed requirements determinationDetailed requirements determination• To ascertain and understand WHAT the To ascertain and understand WHAT the

system will do i.e. the purpose for which system will do i.e. the purpose for which the system is neededthe system is needed

• Sifting through documents, polling Sifting through documents, polling users, conducting interviewsusers, conducting interviews

• Produce a Requirements specification Produce a Requirements specification document from users’ perspectivedocument from users’ perspective


– IS projects fail due to the following causes at this IS projects fail due to the following causes at this stagestage• Limited understanding of the business problem or Limited understanding of the business problem or

opportunityopportunity• Focus on technology requirement instead of business Focus on technology requirement instead of business

requirementrequirement• Incomplete or unclear requirementIncomplete or unclear requirement

– How to deal with these causesHow to deal with these causes• Employ experience professionals Employ experience professionals

– System analystSystem analyst

• Spend more time with the user or client to understand Spend more time with the user or client to understand the needthe need

• Use prototyping to solicit requirement and understandingUse prototyping to solicit requirement and understanding

Phases of IS/IT projectsPhases of IS/IT projectsSystems Design PhaseSystems Design Phase• Deals with how to solve the problem or take Deals with how to solve the problem or take

advantage of the opportunityadvantage of the opportunity• Involves conceptual/logical design and physical Involves conceptual/logical design and physical

designdesign• It’s the overall plan or model for that system. It It’s the overall plan or model for that system. It

includes:includes:– Output designOutput design– Input designInput design– User interface designUser interface design– Database DesignDatabase Design– Processing/logic designProcessing/logic design– Training programs designTraining programs design– Security designSecurity design– Conversion planningConversion planning

• Design tools are used e.g. UML, Flow charts, decision Design tools are used e.g. UML, Flow charts, decision tables, system structure charts, etc.tables, system structure charts, etc.

• The outcome of this stage is a technical specification The outcome of this stage is a technical specification of the system and how it will be usedof the system and how it will be used


Systems Development/Build PhaseSystems Development/Build Phase• This stage involves the creation or This stage involves the creation or

build of the system (i.e. Coding and build of the system (i.e. Coding and testing --- unit testing, system testing testing --- unit testing, system testing and integration testing)and integration testing)

• For SoftwareFor Software– It can be built in-house It can be built in-house – Purchased off the shelvePurchased off the shelve– OutsourcedOutsourced


• Acquisition StrategiesAcquisition Strategies– Custom development (build from Custom development (build from

scratch) in-housescratch) in-house– Purchase software package (and Purchase software package (and

customize it)customize it)– Outsource development to third partyOutsource development to third party


PROS CONS

Custom Development

Advantages of in-house Advantages of in-house developeddeveloped (or bespoke) (or bespoke) software includesoftware include::

• May meet organization’s unique May meet organization’s unique requirementsrequirements..• All business functions for the organization may be All business functions for the organization may be

covered.covered.• User-friendly – menus, forms, reports, combo boxes, User-friendly – menus, forms, reports, combo boxes,

online help, etc.online help, etc.• Organizations need not buy middleware to bridge data Organizations need not buy middleware to bridge data

interchange between two systemsinterchange between two systems• May perform many business functions well and to May perform many business functions well and to

users’ satisfaction. users’ satisfaction. • Allows flexibility and creativityAllows flexibility and creativity• Consistent with existing technology and standardsConsistent with existing technology and standards• Builds technical skills and functional knowledge in-Builds technical skills and functional knowledge in-

househouse

Disadvantages of in-house developed software Disadvantages of in-house developed software include:include:

• Design work has to be accomplished from scratchDesign work has to be accomplished from scratch• Much testing is required and the testing period Much testing is required and the testing period

can be longcan be long• More costly than application software packages.More costly than application software packages.• Programming and maintenance work have to Programming and maintenance work have to

done fully. done fully. • Can be time consuming to develop.Can be time consuming to develop.• Requires significant time and effortRequires significant time and effort• May require missing skillsMay require missing skills• Risk of project failureRisk of project failure

Phases of IS/IT projectsPhases of IS/IT projectsPackaged Software (Turnkey/off-the-shelf Packaged Software (Turnkey/off-the-shelf

software): software): Advantages Advantages of application software packages: of application software packages: • They are pre-tested and proven before they are marketed; They are pre-tested and proven before they are marketed;

hence purchaser requires relatively shorter testing period.hence purchaser requires relatively shorter testing period.• They are readily available for use. They are readily available for use. • They are relatively cheaper than in-house developed They are relatively cheaper than in-house developed

software.software.• They save time and cost for organizations that buy them. They save time and cost for organizations that buy them. • Most of their design work has been accomplished by the Most of their design work has been accomplished by the

developers in advance.developers in advance.• Vendors supply much of the ongoing maintenance and Vendors supply much of the ongoing maintenance and

supportsupport• They reduce the need for internal information systems They reduce the need for internal information systems

resourcesresources• Available for many common business needsAvailable for many common business needs

Disadvantages of application software Disadvantages of application software packages packages are as follows. are as follows.

• They are not user friendly. They are not user friendly. • Many business functions may not be Many business functions may not be

covered. covered. • They require customization which could be They require customization which could be

very costly.very costly.• They may not meet an organization’s They may not meet an organization’s

unique requirements.unique requirements.• Organizations have to buy middleware to Organizations have to buy middleware to

bridge data interchange between 2 bridge data interchange between 2 systemssystems

• Rarely a perfect fit with business needsRarely a perfect fit with business needs


• OutsourcingOutsourcing– Hiring an external vendor, developer, or Hiring an external vendor, developer, or

service providerservice provider– May reduce costs or add valueMay reduce costs or add value– Risks include possiblyRisks include possibly

• Losing confidential informationLosing confidential information• Losing control over future developmentLosing control over future development• Losing learning opportunitiesLosing learning opportunities


• Selecting Acquisition StrategySelecting Acquisition Strategy– Consider each of the following when Consider each of the following when

deciding what strategy to use:deciding what strategy to use:• Business needBusiness need• In-house experienceIn-house experience• Project skillsProject skills• Project managementProject management• Time frameTime frame

Selecting a System Selecting a System Acquisition StrategyAcquisition Strategy

Phases of IS/IT projectsPhases of IS/IT projectsSystems Testing (Is part of Dev/Programming Systems Testing (Is part of Dev/Programming

phase)phase)

• Testing of the computer system or product Testing of the computer system or product should always precede commissioning into should always precede commissioning into serviceservice

• Testing procedures should clearly specifiedTesting procedures should clearly specified• Users test the business scenariosUsers test the business scenarios• Technical personnel test technical aspectTechnical personnel test technical aspect• The following 3 types of testing should be The following 3 types of testing should be

conducted:conducted:– Unit testingUnit testing– System testingSystem testing– Integration testingIntegration testing

• Unit Testing – testing each program Unit Testing – testing each program separatelyseparately

• System Testing – testing each System Testing – testing each module of the software, one after the module of the software, one after the other.other.

• Integration Testing – testing all Integration Testing – testing all modules of the system a single go.modules of the system a single go.

Phases of IS/IT projectsPhases of IS/IT projects• Deployment/Implementation PhaseDeployment/Implementation Phase

– Putting the system into production. This Putting the system into production. This includes:includes:

– installing the system, installing the system, – training users, training users, – re-testing the system, and re-testing the system, and – file conversionsfile conversions– adopting an appropriate changeover method.adopting an appropriate changeover method.

• Testing (or re-testing)Testing (or re-testing)– The following 4 types of testing should be The following 4 types of testing should be

conducted during the Implementation conducted during the Implementation phase of the project:phase of the project:•Unit testingUnit testing•System testingSystem testing•Integration testingIntegration testing•Acceptance testingAcceptance testing

– All these types of testing require test All these types of testing require test plans.plans.

• Unit Testing – testing each program Unit Testing – testing each program separatelyseparately

• System Testing – testing each module of the System Testing – testing each module of the software, one after the other.software, one after the other.

• Integration Testing – testing all modules of Integration Testing – testing all modules of the system a single go.the system a single go.

• Acceptance Testing – provides the final Acceptance Testing – provides the final certifications that the system is ready to be certifications that the system is ready to be used in a production setting. When users and used in a production setting. When users and management are satisfied that the new system management are satisfied that the new system meets their requirements and standards, the meets their requirements and standards, the system is formally accepted.system is formally accepted.

Changeover MethodsChangeover Methods– Ways of introducing a system into Ways of introducing a system into

production are:production are:

• Direct ChangeoverDirect Changeover• Parallel RunParallel Run• Pilot Run/StrategyPilot Run/Strategy• Phased Implementation/ApproachPhased Implementation/Approach

Direct ChangeoverDirect Changeover– A complete changeover from old to new A complete changeover from old to new

system on the cutover daysystem on the cutover day– Normally over a week end or a holiday Normally over a week end or a holiday

periodperiod– Least expensive of the strategiesLeast expensive of the strategies– Ensures total commitment to making the Ensures total commitment to making the

new system worknew system work– It’s risky, as it has very little fallback It’s risky, as it has very little fallback

option to the old system when serious option to the old system when serious problem occurproblem occur


• Parallel RunParallel Run– It involves running the old and new system It involves running the old and new system

together for a specified period of time when the together for a specified period of time when the new system is functioning properlynew system is functioning properly

– It provides opportunity to compare outputs from It provides opportunity to compare outputs from both systemsboth systems

– Less risky, since the organization can fall on the Less risky, since the organization can fall on the old system whenever problem ariseold system whenever problem arise

– It is very expensive as efforts and resources need It is very expensive as efforts and resources need to be duplicated in running the two systemto be duplicated in running the two system


• Pilot runPilot run– One department or other work site serves as a test siteOne department or other work site serves as a test site– It is then replicated throughout the organization when the It is then replicated throughout the organization when the

pilot is found to be working satisfactorilypilot is found to be working satisfactorily– The full gains are not realizable as the new system is The full gains are not realizable as the new system is

implemented in a limited area of the organizationimplemented in a limited area of the organization– Not suitable for non branch situation, where the system Not suitable for non branch situation, where the system

cannot be replicatedcannot be replicated


• Phased ImplementationPhased Implementation– Only parts of a new application or only a few Only parts of a new application or only a few

departments, branch offices at a time are departments, branch offices at a time are convertedconverted

– It allows gradual implementation process to It allows gradual implementation process to take place within an organizationtake place within an organization

– Very suitable for implementing large and Very suitable for implementing large and complex systemscomplex systems

– Minimizes the risk of implementationMinimizes the risk of implementation– Requires effort in ensuring that the Requires effort in ensuring that the

implemented parts are well integrated and implemented parts are well integrated and function as a wholefunction as a whole


Post-Deployment (Post-Post-Deployment (Post-Implementation Review) Phase Implementation Review) Phase – Involves periodic (may be every 2 or 3 years) Involves periodic (may be every 2 or 3 years)

evaluation of the delivered system against evaluation of the delivered system against planned requirements and objectivesplanned requirements and objectives

– Making appropriate modifications to the Making appropriate modifications to the system to conform to changes in the business system to conform to changes in the business organization: e.g. changes in organizational organization: e.g. changes in organizational strategy, goals and objectives, etc.strategy, goals and objectives, etc.

lecture 7 software development

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