Modern Systems Analysisand DesignFifth Edition

Chapter 15System Implementation15.*

Cis339

Learning ObjectivesDescribe the process of coding, testing and converting an organizational information systemDiscuss four installation strategiesDirectParallelSingle locationPhased installationDescribe the deliverables for documenting the system and for training and supporting the usersDistinguish between system and user documentation and determine which types of documentation are necessary for a given information system15.*

Cis339

Learning ObjectivesCompare the many modes available for organizational system training, including self-training and electronic performance support systemsDiscuss the issues of providing support to end usersDiscuss system implementation failureCompare the factor and political models of the implementation processShow how traditional implementation issues apply to Internet-based systems15.*

Cis339

System Implementation

Cis339

System Implementation Six major activitiesCodingTestingInstallationDocumentationTrainingSupportPurposeTo convert final physical system specifications into working and reliable softwareTo document work that has been doneTo provide help for current and future users

15.*

Cis339

The Process of Coding, Testing and InstallationCodingPhysical design specifications are turned into working computer codeTestingTests are performed using various strategiesTesting can be performed in parallel with codingInstallationProcess during which the current system is replaced by the new system

15.*

Cis339

The Process of Coding, Testing and Installation:Deliverables15.*

Cis339

Action

Deliverable

Coding

Code

Program Documentation

Testing

Test scenarios (test plan) and test data

Results of program and system testing

Installation

User guides

User training plans

Installation and conversion plan

The Process of Documenting the System, Training Users and Supporting UsersTwo audiences for documentationThe information systems personnel who will maintain the system throughout its productive lifeThe people who will use the system as part of their daily livesDeliverablesDocumentation, system documentation and user documentationUser training plan, classes and tutorialsUser training modules, training materials and computer-based training aidsUser support plan, help desk, on-line help and bulletin boards and other support mechanisms

15.*

Cis339

Software Application TestingA master test plan is developed during the analysis phase.During the design phase, unit, system and integration test plans are developed.The actual testing is done during implementation.Test plans provide improved communication among all parties involved in testing.

15.*

Cis339

Software Application TestingTypes of TestingInspectionA testing technique in which participants examine program code for predictable language-specific errors, what the code does is not investigated.WalkthroughA peer group review of any product created during the systems development process; also called a structured walkthroughDesk CheckingA testing technique in which the program code is sequentially executed manually by the reviewer

15.*

Cis339

Software Application TestingTypes of TestingUnit TestingEach module is tested alone in an attempt to discover any errors in its code, also called module testingIntegration TestingThe process of bringing together all of the modules that a program comprises for testing purposes. Modules are typically integrated in a top-down, incremental fashion

15.*

Cis339

Software Application TestingTypes of TestingSystem TestingThe bringing together of all the programs that a system comprises for testing purposes. Programs are typically integrated in a top-down, incremental fashionStub TestingA technique used in testing, especially where modules are written and tested in a top-down fashion, where a few lines of code are used to substituted for subordinate modules

15.*

Cis339

Software Application TestingThe Testing ProcessThe purpose of the testing is confirming that the system satisfies requirementsTesting must be plannedTest CaseA specific scenario of transactions, queries or navigation paths that represent a typical, critical or abnormal use of the system, see figure 15-4 for a test case form.Test cases and results should be thoroughly documented so they can be repeated for each revision of an application

15.*

Cis339

Software Application TestingeXtreme ProgrammingCoding and testing are intimately related parts of the same processCode is written, integrated into system and then testedIterative process of testing, fixing bugs and re-testingAll coding is done by two people working together

15.*

Cis339

Software Application TestingAcceptance Testing by UsersThe process whereby actual users test a completed information system, the end result of which is the users acceptance of itAlpha Testing (done in test environment)User testing of a completed information system using simulated data, the following are types of alpha testing:Recovery testingForces the software (or environment) to fail in order to verify that recovery is properly performedSecurity testingVerifies that protection mechanisms built into the system will protect it from improper penetrationStress testingTries to break the systemPerformance testingDetermines how the system performs on the range of possible environments in which it may be used

15.*

Cis339

Software Application TestingAcceptance Testing by UsersBeta Testing (done in real - production- environment)User testing of a completed information system using real data in the real user environment

15.*

Cis339

InstallationThe organizational process of changing over from the current information system to a new oneFour approachesDirect InstallationChanging over from the old information system to a new one by turning off the old system when the new one is turned onParallel InstallationRunning the old information system and the new one at the same time until management decides the old system can be turned off

15.*

Cis339

InstallationSingle location installationTrying out an information system at one site and using the experience to decide if and how the new system should be deployed throughout the organizationPhased InstallationChanging from the old information system to the new one incrementally, starting with one or a few functional components and then gradually extending the installation to cover the whole new system

15.*

Cis339

Planning InstallationConsiderationsData conversionError correction, data must be error-freeUnload from current system, or combined with other data, and load them into the new system files and databases.Planned system shutdown, consider the business cycle of the organizationPlanning for installation begins as early as the analysis phase.

15.*

Cis339

Documenting The SystemSystem documentationDetailed information about a systems design specifications, its internal workings and its functionalityInternal documentationSystem documentation that is part of the program source code or is generated at compile timeExternal documentationSystem documentation that includes the outcome of structured diagramming techniques such as data flow and entity-relationship diagrams

15.*

Cis339

Documenting The SystemUser DocumentationWritten or other visual information about an application system, how it works, and how to use itPreparing user documentationTraditional source has been information systems departmentApplication-oriented documentation, whose purpose is to increase user understanding and utilization of the computing resources, is now often supplied by vendors and users themselves

15.*

Cis339

Training Information System UsersPotential training topicsUse of the systemGeneral computer concepts, computer file and how to copy themInformation system concepts, online and batch processing.Organizational concepts, FIFO inventory accountingSystem management, how to request change to the systemSystem installation

15.*

Cis339

Training Information System UsersTraining methodsResident expertComputer-aided instructionFormal coursesSoftware help componentsTutorialsInteractive training manualsExternal sources, such as vendorsElectronic performance support system (EPSS)Component of a software package or application in which training and educational information is embedded. (tutorial or hypertext)

15.*

Cis339

Supporting Information System UsersSupport is extremely important to users.Providing support can be expensive and time-consuming.One approach is through automationInternet-based online support forums.On-demand fax.Voice response systems.Knowledge bases.

15.*

Cis339

Information CenterAn organizational unit whose mission is to support users in exploiting information technologyStaff might perform the following tasksInstall new hardware or software and set up user accountsConsult with users writing programs in fourth-generation languagesExtract data from organizational databases onto personal computersAnswer basic on-demand questionsProvide a demonstration site for viewing hardware and softwareWork with users to submit system change requests

15.*

Cis339

Help DeskA single point of contact for all user inquiries and problems about a particular information system or for all users in a particular departmentRequiresTechnical skills: extensive knowledge about how to use the system and typical problems that can be encountered.People skills: good listening and communication, dealing with complaints and frustrations

15.*

Cis339

Why Implementation Sometimes FailsTwo conditions necessary for a successful implementationManagement support of the system under developmentInvolvement of users in the development process

15.*

Cis339

Why Implementation Sometimes FailsInsights about implementation processRiskCommitment to the projectCommitment to changeExtent of project definition and planningRealistic user expectations

15.*

Cis339

Implementation success factors 1-Extent to which system is used, user personal stake, system characteristics, user demographics (age, degree, experience), organization support, and performance. 2- Users satisfaction with system.

Cis339

Project Close DownEvaluate teamReassign members to other projectsNotify all affected parties that the development project is ending and that you are switching to operation and maintenance modeConduct post-project reviewsClose out customer contractFormal signoff

15.*

Cis339