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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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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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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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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 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