Matakuliah
Tahun
Versi
: T0234 / Sistem Informasi Geografis
: 2005
: 01/revisi 1
Pertemuan 07
Metode Pengembangan SIG
1
Learning Outcomes
Pada akhir pertemuan ini, diharapkan
mahasiswa akan mampu :
• memilih metode pengembangan SIG yang
sesuai dengan kebutuhan yang ada
(C4, TIK07)
2
Outline Materi
• Materi 1 : Waterfall/ SDLC Model
• Materi 2 : Prototyping Model
3
Waterfall Model (1)
Waterfall Model/SDLC (Skidmore & Wroe, 1988):
Feasibility Study
System Investigation
System Analysis
System Design
Implementation
Review & Maintenance
4
Waterfall Model (2)
• House hunting case study :
1. Feasibility Study (FS) :
Asking the real estate agents & home buyer questions about
whether they would make use of the system being proposed
for development & what the costs & benefits of developing a
GIS would be. If the FS is positive then the project moves to
the second phase.
2. System Investigation & System Analysis
Designer would try to establish the current way in which
home buyers & real estate agents interact to identify houses
for sale in appropriate neighborhoods. This would include
identifying the data & analysis requirements as well as the
preferred output types. A soft systems approach could be
5
used to help with this phase.
Waterfall Model (3)
• House hunting case study :
3. System Design
The GIS data model is constructed using information collected
in the previous phase. In this example, cartographic modeling
techniques might be used to help structure the analysis
requirements of the GIS.
4. Implementation, Review & Maintenance
Now the house-hunting GIS is built & provided to users. This
may be the first opportunity for users to comment on, or interact
with, the system since their involvement in the FS. Users’
experiences inevitably require changes to the system : addition
of new data layers, new analysis techniques or new ways of
visualizing the output.
6
Waterfall Model (4)
• Advantages :
 Provides a very structured framework for the management.
 Extremely important when good time management is an
essential aspect of the project.
 Often easier to budget for the resources required, because
requirements of the system established at an early stage.
• Problems :
 Often fail to address the context of the business.
 The timescale & linear nature of process do not allow for
change in the scope & character of the problem.
 Does not put the user at the center of the system design.
 Offers a very technocentric view of the system development.
 (Because, often considered to favour hierarchical &
centralized systems of information provision)
7
Prototyping Model (1)
The user first defines the basic requirements of the
system.
USER
ANALYST
Basic
Requirements
System to meet
user needs
Experiment
Refine
8
Prototyping Model (2)






The user first defines the basic requirements of the
system.
This could be achieved by using the rich picture &
root definition techniques.
The system designer takes these basic ideas to
construct a prototype system to meet the needs
identified by the user. In GIS Projects such systems
are often described as demonstrators.
The users who identified the original requirements
for the system then experiment with the
demonstration system to see if it is what they
expected.
Other potential users the final system may be
brought in at this stage to see if the system is of
wider value.
The system designer uses their recommendations
9
to improve the system
Prototyping Model (3)









Advantages :
User have a more direct & regular involvement in the design.
Easier to adapt the system in the face of changing circumstances which were not identified at the outset of project.
The system can be abandoned altogether after the first
prototype if it fails to meet the needs of users. Reduces the
cost of developing full systems
If money & time are available a number of prototypes can be
built until the user is satisfied.
Problems :
Prototyping can be difficult to manage. There may be large
numbers of users with large numbers of ideas & opinions.
The resource implications may change following the
development of the first prototype
Knowing when to stop development can also be a problem.
Some GIS designers argue that this is a positive aspect.
10
Penutup
• Mahasiswa diharapkan telah mampu
memilih metode pengembangan SIG yang
sesuai dengan kebutuhan yang ada.
11