Matakuliah
Tahun
Versi
: H0472 / Konsep Sistem Informasi
: 2006
:1
Pertemuan 9
Membuat dan mengelola sistem
informasi
1
Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
• Menjelaskan proses pembuatan dan
mengelola sistem.
2
Outline Materi
• Membuat sistem informasi menggunakan
tradisional sistem.
• Prototype
• Application Package
• End user development
3
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?
4
Introductory case
(Microsoft)…
• “Big system” development
• How does this compare to small, focused
projects?
• How does this compare to the open
source philosophy?
5
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
6
Cost of errors, based on time
of detection
7
How are these phases linked?
8
Alternative approaches for
building systems
• Approaches
– Traditional SDLC
– Prototypes
– Application Packages
– End-user development
• Let’s look at each of these in more detail…
9
What are the differences?
TRADITIONAL SYSTEM LIFE CYCLE
Issue addressed: Control
Summary: Go through a fixed sequence of steps with signoffs after each step and careful documents.
PROTOTYPE
Issue addressed: Knowledge
Summary: Quickly develop a working model of the system; use the model to gain experience and
decide how the final system should operate.
APPLICATION PACKAGES
Issue addressed: Resources and timing
Summary: Purchase an existing information system from a vendor; customize the system if
necessary.
END USER DEVELOPMENT
Issue addressed: Responsiveness
Summary: Provide tools and support that make it practical for end users to develop their own
information systems.
10
Traditional SDLC
• Initiation
– Feasibility study
• Economic, technical and organizational
– Functional spec
– Project plan
• Development
– Look at the diagram on the next slide…
11
Steps in Development
12
Formal development in
action…
• The IMS project
13
Traditional SDLC
• Implementation
– Is there a similar breakdown of tasks?
14
Implementation
15
Traditional SDLC
• Operation and maintenance
16
Prototypes
• Phases
• Advantages & disadvantages
– Used when there is not a clear picture of what
is needed in a system
– Iterative “quick & dirty” mockups
17
Prototype phases…
INITIATION
Users and developers agree to develop a prototype because they need experience with a
working model before designing a final system.
DEVELOPMENT
Working iteratively with users, a prototype is developed and improved. Later, decide
whether to complete the prototype or switch to a traditional life cycle.
IMPLEMENTATION
Accomplish 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 MAINTENANCE
May 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.
18
Prototypes – iterative
development
19
Application packages (COTS)
• Phases
• Advantages & disadvantages
20
Application package phases
INITIATION
May start with user’s or manager’s recognition of a business problem or with a sales call
from a vendor.
DEVELOPMENT
The 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.
IMPLEMENTATION
Implementation 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 MAINTENANCE
Operation 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.
21
Selecting an application package
A
APPLICATION FEATURES
completeness
quality of reports
ease of use
documentation
TECHNICAL FEATURES
use of DBMS
transportability
expandability
VENDOR COMPARISON
financial strength
management strength
committment to product
ECONOMIC COMPARISON
purchase price
maintenance contract
consulting charges
conversion cost
Total weighted score
B
C
A
B
C
WEIGHT
2.5
1.0
2.3
2.8
SCORE
9
7
9
5
5
9
3
9
8
9
6
7
WEIGHTED SCORE
22.5
17.3
20.0
9.0
5.0
9.0
11.5
20.7 19.6
8.4
25.2 19.6
2.8
0.8
1.2
8
2
4
7
5
5
3
6
5
22.4
1.6
4.8
19.6
4.0
6.0
8.4
4.8
6.0
2.0
1.3
2.6
9
6
4
7
9
7
5
8
9
18.0
7.8
10.4
14.0
11.7
18.2
10.0
10.4
23.4
2.0
1.5
0.6
2.3
7
7
5
5
5
7
6
3
7
8
8
5
14.0
10.5
3.0
11.5
10.0
10.5
3.6
6.9
14.0
12.0
4.8
11.5
155.4
172.9 167.7
22
End-user development
• Phases
• Supporting the users
• Advantages & disadvantages
23
End-user system phases
INITIATION
Because the user will develop the information system, a formal functional specification is
unnecessary.
DEVELOPMENT
The 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.
IMPLEMENTATION
Implementation is simplified because the developer is the user.
OPERATION AND MAINTENANCE
End 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.
24
Deciding which methods to
use
• Comparing…
• Synthesizing to get the right balance…
– It’s not all or nothing
25
Closing
• Membuat sistem informasi menggunakan
tradisional sistem.
• Prototype
• Application Package
• End user development
26