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Pertemuan 9Membuat dan mengelola sistem informasi

Matakuliah : H0472 / Konsep Sistem Informasi

Tahun : 2006

Versi : 1

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Learning Outcomes

Pada akhir pertemuan ini, diharapkan mahasiswa

akan mampu :

• Menjelaskan proses pembuatan dan mengelola sistem.

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Outline Materi

• 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

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Traditional SDLC

• Implementation– Is there a similar breakdown of tasks?

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Implementation

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Traditional SDLC

• Operation and maintenance

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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 usedocumentation

TECHNICAL FEATURESuse of DBMStransportabilityexpandability

VENDOR COMPARISONfinancial strengthmanagement strengthcommittment to product

ECONOMIC 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 C

WEIGHTED 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

155.4 172.9 167.7

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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