2.5. Information System
What is a system? A system can be simply defined as a group of interrelated or interacting elements forming a unified whole. A system is a
group of interrelated components working together toward a common goal by accepting inputs and producing outputs in an organized transformation process.
Such a system sometimes called dynamic system has three basic interacting components or functions O’Brien, 1999 :
• Input involves capturing and assembling elements that enter the system to
be processed. For example, raw materials, energy, data, and human effort must be secured and organized for processing;
• Processing involves transformation processes that convert input into
output. Examples are a manufacturing process, the human breathing process, or mathematical calculations;
• Output involves transferring elements that have been produced by
transformation processed to their ultimate destination. For example, finished products, human services, and management information must be
transmitted to their human users. Information is an answer to specific question, in terms of problem solving
within managerialdecision-making activities. Information system is an active object that deals with processes and information and its main purpose is to inform
users and to help in decision-making process. Information system also is a system that accepts resources data as input and processes them into products
information as output.
According to O’Brien 1999, an information system depends on the resources of people end users and IS specialists, hardware machines and
media, software programs and procedures, data data and knowledge bases, and networks communication media and network support to perform input,
processing, output, storage, and control activities that convert data resources into information products. Figure 2.2 illustrated the components of an information
system.
Figure 2.2.The components of information system O’Brien,1999
2.5.1. Information System Development
When the systems approach to problem solving is applied to the development of information system solutions to business problems, it is called
information systems development of application development. Most computer- based information systems are conceived, designed, and implemented using some
form of systematic development process. In this process, end users and
information specialists design information systems based on an analysis of the information requirements of an organization. Thus, a major part of this process is
known as systems analysis and design. Using the systems approach to develop information system solutions involves a multi steps process called the information
systems development cycle, also known as the systems development life cycle SDLC. Figure 2.3 illustrates each stage of this process, which includes the steps
of 1 investigation, 2 analysis, 3 design, 4 implementation, and 5 maintenance.
In many cases, the traditional SDLC have to be modified because of its limitation, such as costly and time consuming, inflexible and discourage change,
and ill-suited to decision making Hoffer, 2002 in Jayarsa, 2005. One alternative solution is to develop prototyping. According to O’Brien 1999, prototyping is
the rapid development and testing of working model, or prototypes, or new application in an interactive, iterative process that can be used by both systems
analysts and end user. Prototyping is an interactive process that combines stages of the traditional systems development Figure 2.4.
The advantages of prototyping are users involved in design and captures requirements in concrete form Hoffer, 2002 in Jayarsa, 2005. Prototyping
makes the development process faster and easier for system analysts, especially for projects where end user requirements are difficult to define.
Figure 2.3. The traditional information system development cycle
O’Brien,1999
Figure 2.4. Prototyping development stages O’Brien, 1999
2.6. Geographic Information System GIS
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