361103834-CHAPTER-5-SYSTEM-IMPLEMENTATION-AND-SUPPORT-pdf.pdf

System analysis and design

1. SYSTEM IMPLEMENTATION AND
SUPPORT
CHAPTER 5
DFC3043 SYSTEM ANALYSIS & DESIGN

2. LEARNING OUTCOMES
5.1 Understand system development
5.2 Understand testing in a project
5.3 Explain system implementation
5.4 Understand systems support and security

3. 5.1 UnderstandSystem Development
5.1.1 Differentiate system development tools:
a.Modeling
b.Prototyping
c.CASE Tools
5.1.2 Explain the coding process

4. 5.1.1 Differentiate system development tools
Systemsanalystmustknowhowtouseavarietyoftechniques,
suchasModelling,Prototyping,andComputer-AidedSystems
Engineering(CASE)tools.
Why:
Tounderstandingbusinessoperations
Toplaninateamenvironment,whereinputfromusers,
managers,andITstaffcontributestothesystemdesign
ModellingPrototypingCASE Tools

5. MODELING
•Modelingproduces a
graphical representation of
a concept or process that
systems developers can
analyze, test, and modify.
•A systems analyst can
describe and simplify an
information system by using
a set of business, data,
object, network, and
process models.
PROTOTYPING
•Prototyping tests system
concepts and provides an
opportunity to examine
input, output, and user
interfaces before final
decisions are made.
•A prototype is an early
working version of an
Information system.
CASE TOOLS
•Computer-aided systems
engineering (CASE), also called
computer-aided software
engineering, is a technique that
uses powerful software, called CASE
tools, to help systems analysts
develop and maintain information
systems.
•
•CASE tools provide an overall
framework for systems
development and support a wide
variety of design methodologies,
including structured analysis and
object-oriented analysis.
5.1.1 Differentiate system development tools

6. MODELING PROTOTYPING CASE TOOLS
5.1.1 Differentiate system development tools

7. 5.1.1 Differentiate system development tools
Modelingproducesagraphicalrepresentationofaconceptorprocessthat
systemsdeveloperscananalyze,test,andmodify.
Asystemanalystcandescribeandsimplifyaninformationsystembyusing
asetofbusiness,data,object,network,andprocessmodels.
Eg:
Abusinessmodel/requirementsmodel,describestheinformationthat
asystemmustprovide.
Adatamodeldescribesdatastructureanddesign.
Anobjectmodeldescribesobjects,whichcombinedataandprocesses.
Anetworkmodeldescribesthedesignandprotocolsof
telecommunicationslinks.
Aprocessmodeldescribesthelogicthatprogrammersusetowrite
codemodules.
Althoughthemodelsmightappeartooverlap,theyactuallyworktogether
todescribethesameenvironmentfromdifferentpointsofview.
Modelling

8. Reasons for Modeling
Learning from the modelingprocess
Reducing complexity by abstraction
Remembering all of the details
Communicating with other development
teams members
Communicating with a variety of
stakeholders
Documenting what was done for future
maintenance/enhancement
Examples of Models Used in Analysis Phase
Data flow diagram (DFD)
Entity-relationship diagram (ERD)
Decision Table
Examples of Model Used in Design
Screen layout
Report layout
System flowchart
Database schema / Data
Dictionary
Network diagram
Modelling
5.1.1 Differentiate system development tools

9. Prototyping Purpose:
To tests system concepts and provides an opportunity to examine input,
output, and user interfaces before final decisions are made.
A prototype is an early working version of an information system.
Just as an aircraft manufacturer test a new design in a wind tunnel,
systems analysts construct and study information systems prototypes.
Advantage:
A prototype can serve as an initial model that is used as benchmark to
evaluate the finished system, or the prototype itself can develop into the
final version of the system.
Either way, prototyping speeds up the development process significantly.
Possible Disadvantage:
Important decisions might be made too early, before business or IT issues
are understood thoroughly.
A prototype based on careful fact finding and modelling techniques, however
can be an extremely valuable tool.
Prototyping
5.1.1 Differentiate system development tools

10. 5.1.1 Differentiate system development tools
CASE Tools

11. Computer-aided systems engineering (CASE), also called computer-aided software
engineering
What:
A technique that uses powerful software, called CASE Tools
CASE tools provide an over all framework for systems development and support a wide
variety of design methodologies, including structured analysis and object-oriented
analysis.
Reason: to help system analyst’s develop and maintain information systems.
How:
Because CASE tools make it easier to build an information system, they boost it
productivity and improved the quality of the finished product.
Traditional CASE tools system developers often use project management tools, such as
Microsoft Project, and special –purpose charting tools, such as Microsoft Visio.
a system analyst’s can use Visio to create many different types of diagrams,
including block diagrams. Building plans, forms and charts, maps, network
diagrams, and organization charts.
Example of CASE software are:
Microsoft Visio
Rational Rose
Three leading CASE tool suppliers: Visible Systems Corporation, TelelogicSoftware, and
Rational Software
CASE Tools
5.1.1 Differentiate system development tools

12. CASE Tool Examples: Visible Analyst
Visible Systems Corporation is an important player in the software development market
Also provides a full range of Help features, including the error message analysis screen
CASE Tools
5.1.1 Differentiate system development tools

13. CASEToolExamples:RationalSoftware
IBMoffersmanysystemsdevelopmentandmodellingproducts,includinga
powerfultoolcalledRationalSystemArchitect
Stressesmodellingandcollaboration,andisasuiteoftoolsthatcanalign
processes,information,andtechnologies
CASE Tools
5.1.1 Differentiate system development tools

14. SYSTEM DEVELOPMENT –
5.1 2 CODING PROCESS
Codingistheprocessofturningprogramlogic
intospecificinstructionsthatthecomputer
systemcanexecute.
Workingfromaspecificdesign,aprogrammer
usesaprogramminglanguagetotransform
programlogicintocodestatements.

15. 5.2.1 Explain the importance of software quality assurance
5.2.2 Differentiate the types of software testing:
-Unit testing
-Integration testing
-System testing
5.2.3 Differentiate between program, system, operations and
user documentation
5.2 Understand testing in a project

16. 5.2.1 Explain the importance of software quality assurance.
Introduction:
Thesystemdesignspecificationservesasablueprintforconstructing
thenewsystem
Theinitialtaskisapplicationdevelopment
Beforeachangeovercanoccur,thesystemmustbetestedand
documentedcarefully,usersmustbetrained,andexistingdatamustbe
converted
Aformalevaluationoftheresultstakesplaceaspartofafinalreportto
management

17. •Software Engineering
•Capability Maturity Model (CMM)
•Capability Maturity Model
Integration (CMMI)
•Process improvement
•CMMI tracks an organization's
processes, using five maturity layers
5.2.1 Explain the importance of software quality assurance.

18. •International Organization for Standardization (ISO)
–Many firms seek assurance that software systems will meet rigid
quality standards
–ISO 90003:2004
–ISO requires a specific development plan
5.2.1 Explain the importance of software quality assurance.

19. 5.2.2 Differentiate the types of software testing
Three types of software
testing
Unit Testing
Integration Testing
System Testing
You should regard thorough
testing as a cost-effective
means of providing a quality
product
19

20. Unit Testing:
Unit testing involves individually testing unit of code separately to make
sure that it works on its own, independent of the other units.
Eg: Testing a function; whether loop or statement in a program is working
properly or not than this is called asunit testing
Integration Testing:
Test the modules to ensure whether they are integrating properly or not
by combining the modules and tested as a group.
Eg: Tester have to test the keyboard of a computer than it is a unit testing
but when tester have to combine the keyboard and mouse of a computer
together to see its working or not than it is theintegration testing.
It is prerequisite that for performing integration testinga system must be
unit tested before.
5.2.2 Differentiate the types of software testing

21. System Testing:
Tester test the complete system as a whole to check whether the system is
properly working or vice versa as per the requirements or not.Testers
always have to concentrate on both functional and non-functional testing
like performance, load, stress, security and recovery testing
In summary: in system testing the testers test the complete system as a
whole.
Eg: Test the whole functionality and non functionality of the system
interactions between all module in Laundry Management System as one
single system.
It is prerequisite that for performing system testinga system must be unit
tested and integration tested before.
5.2.2 Differentiate the types of software testing

22. 5.2.3 Differentiate between program, system,
operations, and user documentation.
Program Documentation
System Documentation
Operations Documentation
User Documentation
Systems analysts usually are responsible for preparing
documentation to help users learn the system
22

23. System documentation describes the system’s
functions and how they are implemented.
System documentation includes data dictionary
entries, data flow diagrams, object models, screen
layouts, source documents, and the systems request
that initiated the project.
Program documentation describes the inputs, outputs, and
processing logic for all program modules.
5.2.3 Differentiate between program, system,
operations, and user documentation.

24. Operationsdocumentationcontainsalltheinformationneededfor
processinganddistributingonlineandprintedoutput.Typicalexamplesof
operationsdocumentationincludesthefollowinginformation:
Program,systemsanalyst,programmer,andsystemidentification
Schedulinginformationforprintedoutput,suchasreportrun
frequencyanddeadlines
Inputfilesandwheretheyoriginate;andoutputfilesanddestinations
E-mailandreportdistributionlists
Specialformsrequired,includingonlineforms
Errorandinformationalmessagestooperatorsandrestartprocedures
Specialinstructions,suchassecurityrequirements
Operationsdocumentationshouldbeclear,concise,andavailableonlineif
possible.
5.2.3 Differentiate between program, system,
operations, and user documentation.

25. WhatisUserDocumentation?
Userdocumentationconsistsof
instructionsandinformationtouserswho
willinteractwiththesystemandincludes
usermanuals,Helpscreens,andtutorials.
Programmersorsystemsanalystsusually
createprogramdocumentationandsystem
documentation.
5.2.3 Differentiate between program, system,
operations, and user documentation.

26. User Documentation
Effective online documentation is
an important productivity tool
Written documentation material
also is valuable
26
5.2.3 Differentiate between program, system,
operations, and user documentation.

27. 5.3 Explain System Implementation
5.3.1 List the main steps in system implementation
5.3.2 Explain system installation and evaluation
5.3.3 Outline system installation and evaluation checklist

28. 5.3 Explain system implementation.
Management Approval
After system testing is complete, developer team need to
present the results to management
If system testing produced no technical, economical, or
operational problems, management determines a schedule for
system installation and evaluation
28

29. 5.3.1 List the main steps in system implementation.
The new system now is ready to go to work. Now, you will carry out the
remaining steps in systems implementation:
1.Prepare a separate operational and test environment
2.Provide trainingfor users, managers, and IT staff
3.Perform data conversion and system changeover
4.Carry out a post-implementation evaluation of the system
5.Present a final report to management
29

30. 1. Operational and test environment
Theenvironmentfortheactualsystemoperationiscalledthe
operationalenvironmentorproductionenvironment.
Theenvironmentthatanalystsandprogrammersuseto
developandmaintainprogramsiscalledthetest
environment.
Aseparatetestenvironmentisnecessarytomaintainsystem
securityandintegrityandprotecttheoperational
environment.
5.3.2 System Installation And Evaluation

31. 2. Provide training for users, managers, and IT staff
Training Plan-it is essential to provide the right training for the right people at the
right time, specific training topics, identify the objectives, and determine how the
company will provide training. The main choices are to obtain training from vendors,
outside training firms, or use IT staff and other in-house resources.
VendorTraining-Manyhardwareandsoftwarevendorsoffertrainingprogramsfreeorata
nominalcostfortheproductstheysell.Thetrainingusuallyisconductedatthevendor’ssite
byexperiencedtrainerswhoprovidevaluablehands-onexperience.Vendortrainingoften
givesthebestreturnonyourtrainingdollarsbecauseitisfocusedonproductsthatthe
vendordeveloped.ManyvendorsofferWeb-basedtrainingoptions,includingWebinars,
podcasts,andtutorials.
In-houseTraining-TheITstaffanduserdepartmentsoftenshareresponsibilityfor
developingandconductingtrainingprogramsforinternallydevelopedsoftware.Ifyour
organizationhasahelpdesk,thestaffmightbeabletohandleinternallyusertraining.
5.3.2 System Installation And Evaluation

32. 3.DataConversion
Dataconversionisanimportantpartofthesysteminstallationprocess.Duringdataconversion,
existingdataisloadedintothenewsystem.
DataConversionStrategy-Whenanewsystemreplacesanexistingsystem,youshouldautomate
thedataconversionprocess,ifpossible.
Theoldsystemmightbecapableofexportingdatainanacceptableformatforthenewsystemor
inastandardformat.Ifastandardformatisnotavailable,youmustdevelopaprogramtoextract
thedataandconvertittoanacceptableformat.
5.3.2 System Installation And Evaluation

33. 3. System Changeover
System changeover is the process of putting the new information
system online and retiring the old system.
Changeover can be rapid or slow, depending on the method. The
four changeover methods are :
1.direct cutover
2.parallel operation
3.pilot operation
4.phased operation
5.3.2 System Installation And Evaluation

34. System Changeover
34

35. System Changeover
DirectCutover
Involvesmoreriskthanother
changeovermethods
Companiesoftenchoosethedirect
cutovermethodforimplementing
commercialsoftwarepackages
Cyclicalinformationsystems
usuallyareconvertedusingthe
directcutovermethodatthe
beginningofaquarter,calendar
year,orfiscalyear
35

36. System Changeover
ParallelOperation
–Easiertoverifythatthenewsystemis
workingproperlyunderparalleloperation
thanunderdirectcutover
–Runningbothsystemsmightplaceaburden
ontheoperatingenvironmentandcause
processingdelay
–Isnotpracticaliftheoldandnewsystemsare
incompatibletechnically
–Alsoisinappropriatewhenthetwosystems
performdifferentfunctions
36

37. System Changeover
PilotOperation
Thegroupthatusesthenewsystemfirstis
calledthepilotsite
Theoldsystemcontinuestooperatefor
theentireorganization
Afterthesystemprovessuccessfulatthe
pilotsite,itisimplementedintherestof
theorganization,usuallyusingthedirect
cutovermethod
Isacombinationofparalleloperationand
directcutovermethods
37

38. System Changeover
PhasedOperation
Yougiveapartofthesystemtoallusers
Theriskoferrorsorfailuresislimitedtothe
implementedmoduleonly
Islessexpensivethanfullparalleloperation
Isnotpossible,however,ifthesystemcannot
beseparatedeasilyintologicalmodulesor
segments
38

39. System Changeover summary
risk vs cost
39

40. 4. Post-implementation Evaluation
A post-implementation evaluation assesses the overall quality of the information system.
The evaluation verifies that the new system meets specified requirements, complies with
user objectives, and produces the anticipated benefits.
5. Final Report to Management
The final report to management marks the end of systems development work. Your report
should include the following:
• Final versions of all system documentation
• Planned modifications and enhancements to the system that have been identified
• Recap of all systems development costs and schedules
• Comparison of actual costs and schedules to the original estimates
• Post-implementation evaluation, if it has been performed
5.3.2 System Installation And Evaluation

41. Data Conversion
Data Conversion Security and Controls
The developer team must ensure that all system control measures are in
place and operational to protect data from unauthorized access and to
help prevent erroneous input
Some errors will occur
It is essential that the new system be loaded with accurate, error-free
data
41

42. 5.4 Understand Systems Support and Security
5.4.1 Explain the system support and security phase
5.4.2 Identify user support:
User training
Help desk
5.4.3 Explain various types of maintenance:
Corrective maintenance
Adaptive maintenance
Perfective maintenance
Preventive maintenance
5.4.4 Identify tools for system maintenance
5.4.5 Explain the system security and backup
5.4.6 Identify three elements of system security

43. 5.4.1 Explain the system support and security phase
Systems support and security is the final phase in the systems development
life cycle.
Managing systems support and security involves three main concerns:
1.user expectations
2.system performance
3.security requirements

44. 5.4.2 Identify user support:
User Training
New employees must be trained on the
company’s information systems.
The main objective is to show users how
the system can help them perform their
jobs.
The training could include online support
via e-mail, a special Web site, a revision
to the user guide, a training manual
supplement, or formal training sessions.
Help Desks
To make data more accessible and to empower users,
many IT departments create help desks.
A help desk is a centralized resource staffed by IT
professionals who provide users with the support they
need to do their jobs.
A help desk has three main objectives:
1.Show people how to use system resources more
effectively
2.Provide answers to technical or operational questions
3.Make users more productive by teaching them how to
meet their own information needs
A help desk often is called an information center(IC)
because it is the first place users turn when they need
information or assistance.

45. 5.4.3 Explain various types of maintenance:
CorrectiveMaintenance
Correctivemaintenancediagnosesandcorrectserrorsinanoperationalsystem.
Toavoidintroducingnewproblems,allmaintenanceworkrequirescarefulanalysis
beforemakingchanges.
AdaptiveMaintenance
Adaptivemaintenanceaddsenhancementstoanoperationalsystemandmakes
thesystemeasiertouse.
PerfectiveMaintenance
Perfectivemaintenanceinvolveschanginganoperationalsystemtomakeitmore
efficient,reliable,ormaintainable.Requestsforcorrectiveandadaptive
maintenancenormallycomefromusers,whiletheITdepartmentusually
initiatesperfectivemaintenance.
PreventiveMaintenance
Toavoidproblems,preventivemaintenancerequiresanalysisofareaswhere
troubleislikelytooccur.Likeperfectivemaintenance,theITdepartmentnormally
initiatespreventivemaintenance.Preventivemaintenanceoftenresultsin
increasedusersatisfaction,anddecreaseddowntime.
Whatissystemmaintenance?
Systemmaintenanceistheprocessofrefiningthesystemto
makesureitcontinuestomeetbusinessneeds.

46. 5.4.4 Identify tools for system maintenance
Many CASE tools include system evaluation and maintenance features, including the following
examples:
Performance monitor that provides data on program execution times
Program analyzerthat scans source code, provides data element cross-reference
information, and helps evaluate the impact of a program change
Interactive debugging analyzerthat locates the source of a programming error
Reengineering tools
Automated documentation
Network activity monitor
Workload forecasting tool

47. BACKUP AND RECOVERY
Every system must provide for data backup and recovery.
Backup refers to copying data at prescribed intervals, or continuously.
Recovery involves restoring the data and restarting the system after an interruption.
An overall backup and recovery plan that prepares for a potential disaster is called a
disaster recovery plan.
BACKUP TYPES
Backups can be full, differential, incremental, or continuous.
Backup Policies
The cornerstone of business data protection is a backup policy, which contains
detailed
instructions and procedures. An effective backup policy can help a firm continue
business
5.4.5 Explain the system security and backup

48. BACKUP TYPES
Backups can be full, differential, incremental, or continuous.
Backup Policies
The cornerstone of business data protection is a backup policy, which contains detailed
instructions and procedures.
An effective backup policy can help a firm continue business operations and survive a
catastrophe.
The backup policy should specify backup media, backup types, and retention periods.
5.4.5 Explain the system security and backup

49. Backup Types
49
Very Famous!
5.4.5 Explain the system security and backup

50. To provide system security, you must consider six separate but interrelated
levels:
physical security,
network security,
application security,
file security,
user security, and
procedural security.
Like the chain shown in Figure 12-26, system security is only as strong as the
weakest link.
5.4.5 Explain the system security and backup

51. Security is a vital part of every computer
system
System Security Concepts, CIA triangle:
Integrity
Availability
Security policy / Confidentiality
Also known as:
3 Elements of System Security
51
3 Elements of System Security
Very Famous!
5.4.6 Identify three elements of system security

52. 5.4.6 Identify three elements of system security
SystemSecurityElements
TheCIAtriangleinFigure12-20showsthethreemain
elementsofsystemsecurity:confidentiality,integrity,
andavailability.
Confidentialityprotectsinformationfrom
unauthorizeddisclosureandsafeguardsprivacy.
Integritypreventsunauthorizedusersfromcreating,
modifying,ordeletinginformation.
Availabilityensuresthatauthorizedusershavetimely
andreliableaccesstonecessaryinformation.

53. SUMMARY
The systems implementation phase consists of application development, testing, installation,
and evaluation of the new system
In addition to system documentation, analysts and technical writers also prepare operations
documentation and user documentation
During the installation process, you establish an operational, or production, environment for
the new information system that is completely separate from the test environment.
Everyone who interacts with the new information system should receive training appropriate
to his or her role and skills.
Data conversion often is necessary when installing a new information system. When a new
system replaces a computerized system, you should automate the data conversion process if
possible.
System changeover is the process of putting the new system into operation.
A post-implementation evaluation assesses and reports on the quality of the new system and
the work done by the project team.
The final report to management includes the final system documentation, describes any
future system enhancements that already have been identified, and details the project costs.
The report represents the end of the development effort and the beginning of the new
system’s operational life.