MEMBUAT DAN MENGELOLA SISTEM INFORMASI

Pertemuan-9

Mata Kuliah : CSS-113 , Konsep Sistem InformasiTahun Akademik : 2012/2013

Sasaran Pembelajaran

Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu :

Menjelaskan proses pembuatan dan mengelola sistem.10-1

Materi Pokok

• Membuat sistem informasi menggunakan tradisional sistem.

• Prototype• Application Package• End user development

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Building and Maintaining Information Systems

• Phases of information systems• Alternative approaches for building information

systems• Traditional SDLC• Prototypes• Application Packages• End-User Development• How to choose which methods to use?

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Introductory case (Microsoft)…

• “Big system” development• How does this compare to small, focused projects?• How does this compare to the open source

philosophy?

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Phases of any information system

• Remember these? From the first chapter, and it was a mid-term question…

• Phases (generically speaking)– Initiation– Development– Implementation– Operation and maintenance

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Cost of errors, based on time of detection

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How are these phases linked?

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Alternative approaches for building systems

• Approaches– Traditional SDLC– Prototypes– Application Packages– End-user development

• Let’s look at each of these in more detail…

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What are the differences?

TRADITIONAL SYSTEM LIFE CYCLEIssue addressed: ControlSummary: Go through a fixed sequence of steps with signoffs after each step and

careful documents.

PROTOTYPEIssue addressed: KnowledgeSummary: Quickly develop a working model of the system; use the model to gain

experience and decide how the final system should operate.

APPLICATION PACKAGESIssue addressed: Resources and timingSummary: Purchase an existing information system from a vendor; customize

the system if necessary.

END USER DEVELOPMENTIssue addressed: Responsiveness Summary: Provide tools and support that make it practical for end users to

develop their own information systems.

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Traditional SDLC

• Initiation– Feasibility study• Economic, technical and organizational

– Functional spec– Project plan

• Development– Look at the diagram on the next slide…

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Steps in Development

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Formal development in action…• The IMS project

Traditional SDLC

• Implementation– Is there a similar breakdown of tasks?

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Implementation

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Traditional SDLC• Operation and maintenance

Prototypes

• Phases• Advantages & disadvantages– Used when there is not a clear picture of what is

needed in a system– Iterative “quick & dirty” mockups

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Prototype phases…

INITIATIONUsers and developers agree to develop a prototype because they need

experience with a working model before designing a final system.

DEVELOPMENTWorking iteratively with users, a prototype is developed and improved. Later,

decide whether to complete the prototype or switch to a traditional life cycle.

IMPLEMENTATIONAccomplish parts of implementation along with development as users work with

the prototype system. Dispel skepticism about whether the system will meet users’ needs.

OPERATION AND MAINTENANCEMay be similar to a traditional life cycle. May require less maintenance because

the system fits users’ needs more accurately. May require more maintenance because the system is not constructed as well.

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Prototypes – iterative development

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Application packages (COTS)• Phases• Advantages & disadvantages

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Application package phases

INITIATIONMay start with user’s or manager’s recognition of a business problem or with a

sales call from a vendor.

DEVELOPMENTThe vendor develops the software, although the purchase still performs some

typical development activities, such as determining detailed requirements. Development may include customization of the software and user documentation.

IMPLEMENTATIONImplementation starts by deciding exactly how the package will be used. It

often relies on the vendor’s staff because they have the greatest knowledge of the system.

OPERATION AND MAINTENANCEOperation occurs as it would with a traditional life cycle. Maintenance is

different because the vendor maintains the software based on requests from customers and demands of the market.

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Selecting an application package

APPLICATION FEATUREScompletenessquality of reportsease of usedocumentationTECHNICAL FEATURESuse of DBMStransportabilityexpandabilityVENDOR COMPARISONfinancial strengthmanagement strengthcommittment to productECONOMIC COMPARISONpurchase pricemaintenance contractconsulting chargesconversion cost

Total weighted score

WEIGHT2.51.02.32.8

2.80.81.2

2.01.32.6

2.01.50.62.3

SCORE9 7 89 5 95 9 63 9 7

8 7 32 5 64 5 5

9 7 56 9 84 7 9

7 5 77 7 85 6 85 3 5

A B C A B CWEIGHTED SCORE22.5 17.3 20.0 9.0 5.0 9.011.5 20.7 19.6 8.4 25.2 19.6

22.4 19.6 8.4 1.6 4.0 4.8 4.8 6.0 6.0

18.0 14.0 10.0 7.8 11.7 10.410.4 18.2 23.4

14.0 10.0 14.010.5 10.5 12.0 3.0 3.6 4.811.5 6.9 11.5

155.4 172.9 167.710-19

End-user development

• Phases• Supporting the users• Advantages & disadvantages

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End-user system phases

INITIATIONBecause the user will develop the information system, a formal functional

specification is unnecessary.

DEVELOPMENTThe user develops the system using tools that do not require a professional

level of programming knowledge. Information systems that are critical to the company or have many users require more extensive testing, documentation, and usage procedures.

IMPLEMENTATIONImplementation is simplified because the developer is the user.

OPERATION AND MAINTENANCEEnd users are responsible. Long-term maintenance and technical quality

become larger issues because the end users have other work to do and are not professional programmers.

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Deciding which methods to use

• Comparing…• Synthesizing to get the right balance…– It’s not all or nothing

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Closing

• Membuat sistem informasi menggunakan tradisional sistem.

• Prototype• Application Package• End user development

========== thanks 4 your attention ==========

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