In this article, I will discuss to hit several things related to system development, among others: the importance of system development, principles in system development, system development alive cycle, and approach itself system development, difference between methodology, method and algorithm, several classifications from system development live cycle, technique in system development and difference between system analyst and programmers.
The Importance of Developing an Information System
System cannot then survive a spell of time. Because of that necessary, so we have to change towards system by repair old ones system and if necessary to replaced old ones system. There are some things provide a basis for the mentioned, among others:
There are troubleshoot in old ones system
Troubleshoot that meant here like existence irregularity in old ones system so that the result is disagreeing with supposed. The example: found errors both for intentional and or not that causes data at one particular company can not well guaranteed the truth, existence chances or opportunity of member from system to do deceit. Other troubleshoot also can be caused by organization growth. The example is in a company trade that bloom previous only limit of in city now up to national even international. Organization or company growth to force system that has previous must be accustomed with work need from company, previous transaction for example has conventional now modern with makes use internet.
To reaches opportunities
A system must be repair or developed also caused to reaches to chance from an organization or company. For example in manager level in a company to demanded for fast produce a wisdom so that company to get profit more many, so that company make use decision supporter system so that wisdom that got quicker.
Existence some directives
A system must be innovated or developed also caused by external factor likes government. Government wisdoms existence force a company to use system not oppose against wisdom.
Development or maker a system sure does not consume cost a little, so that organization must wisely determine to what system that used to still proper to worn or must be developed or replaced. several indicators that can be used to see a system must be repaired: complaint from customer, goods delivery often delay, late salary payment, irregularity finance, stock too tall, investment inefficient, etc.
The Purpose or Goal of Developing an Information System
Performance, measurable with 2 parameters that is throughput and response time. Throughput is transaction quantity that could be finished at one time certain. Response time is amount time castaway at the time of transaction process transfer. So, increase performance aim to increase amount of transaction with time as soon as possible.
Information, quality enhanced from information. Quality from this information will determine wisdom from organization.
Economy, increase profit with cost minimum.
Control, control used to controls or detect errors existence at one particular system.
Efficiency, differ from economical that focus in finance, efficiency here maximize resource utilization.
Service, service enhanced by a system.
Principles of Developing an Information System
Several principles that must be use at process of system development are:
System is used for management
This is main principle that must be remember at process of system development, because final purpose from this system development is supports need that need by side management.
System that developed to be big capital investment
Development a system sure need big capital so that also is an investment to that is company. Several things that must be attention towards capital investments: all alternative must investigate, and best investment must valuable.
System that developed to need educated person
Principal component from a system is who uses there are system. So, a good system without be supported by good resource also sure will not produce optimal result.
Work stage and duties that must be finished at process of system development.
To finish system development must beforehand prepare good planning and in working that determined. These work stages usually explainable in system live cycle. System live cycle will be discusses at next point.
System development process must not in a series
Is not forever a system development in series, several steps be run concurrent. Of course, will save time and give attention work result so that keep the optimal result.
Don’t be afraid to cancel the project
A plan that made be done analysis, and if in analysis stage obvious plan cannot be continued in implementation stage because a matter, so that project can be cancelled. Of course this aim for that company or organization, so that doesn’t happen loss either from time aspect and energy and or economy problem.
Documentation is very good for next system development. Documentation should be creating from beginning system development until process finished.
Approaches of Developing a System
There is some approach that used for system development and may visible from several viewpoints, among others:
Methodology that Used
– Classical approach
– Structured approach
Target that Want Achieved
– Piecemeal approach
– System approach
Manner Determines Need from System
– Bottom-up approach
– Up-bottom approach
Manner Develop it
– Totally system approach
– Modular approach
Technology that used
– Great loop approach
– Evolutionary approach
The Meaning of Methodology, Method and Algorithm
Method is a systematic way to achieve a goal
Methodology is a set of methods, procedures, working concepts, and rules used by a science, art and other disciplines, (Jogiyanto.HM, Analyst Design and Information Systems, Hal. 59)
Algorithm is a set of procedures used to complete a problem.
System Development Life Cycle Models
This model is a model one-way starting from the preparation stage until treatment. This stage includes the planning, design a system, implementation, verification and maintenance. Planning stage is defining the problem and determine what work needs to be done, who is working on and when. The next stage is design. This stage aims to design problems in accordance with the issues that have been defined. Next is the implementation, the application of the design are made. Once the design is implemented the next verification and implementation. This stage is a stage in which most financing, because the system is still in use then there is still financing.
The most visible difference between the models with the waterfall model iterative this is the process of developing the system. If the waterfall in one direction, whereas in iterative there is a testing and evaluation of the test whether the application can still be used or not. If the system was not good to use it will be done to identify problems and come back again to be developed.
The spiral model, also known as the spiral lifecycle model, is a systems development lifecycle (SDLC) model used in information technology (IT). This model of development combines the features of the prototyping model and the waterfall model. The spiral model is favored for large, expensive, and complicated projects.
The steps in the spiral model can be generalized as follows:
- The new system requirements are defined in as much detail as possible. This usually involves interviewing a number of users representing all the external or internal users and other aspects of the existing system.
A preliminary design is created for the new system.
A first prototype of the new system is constructed from the preliminary design. This is usually a scaled-down system, and represents an approximation of the characteristics of the final product.
A second prototype is evolved by a fourfold procedure: (1) evaluating the first prototype in terms of its strengths, weaknesses, and risks; (2) defining the requirements of the second prototype; (3) planning and designing the second prototype; (4) constructing and testing the second prototype.
At the customer’s option, the entire project can be aborted if the risk is deemed too great. Risk factors might involve development cost overruns, operating-cost miscalculation, or any other factor that could, in the customer’s judgment, result in a less-than-satisfactory final product.
The existing prototype is evaluated in the same manner as was the previous prototype, and, if necessary, another prototype is developed from it according to the fourfold procedure outlined above.
The preceding steps are iterated until the customer is satisfied that the refined prototype represents the final product desired.
The final system is constructed, based on the refined prototype.
The final system is thoroughly evaluated and tested. Routine maintenance is carried out on a continuing basis to prevent large-scale failures and to minimize downtime.
Tools for Developing a System
To perform the steps in accordance with methodology of some system, the required equipment. Tools that are usually used as a picture or diagram, or graph, like:
Data Flow diagram
Diagrams on used to describe a certain method, there are some graph more has general, among others:
Chart to describe the activities (activity charting), such as flow diagram system, eyebrow draft program, flow diagram paper, flow diagram relationship database, flow diagram process, and the Gantt chart.
Chart to describe layout
Chart to describe staff connection, like: work distribution draft and organization draft.
Techniques Used in Developing a System
Techniques that used for developing a system, like:
Project management techniques, such as CPM (Critical Path Method) and pert (Program Evaluation and Review Technique). This technique is used to project schedule.
Fact-finding techniques, the techniques that can be used to collect data and find the facts in the learning activities that have system. For example, interview technique, observation, questionnaire, sample collection.
Technical analysis of cost / benefit
Technical inspection / walkthrough
System Analyst VS Programmers
A System Analyst must have the skills and knowledge such as:
1. Data processing techniques, computer technology and computer programming. Usually a systems analyst programmer started from, so certain are the programming language that is required for an analyst job.
2. Knowledge about business in general
Business application is an application used at the moment so hopefully a business analyst to understand knowledge in general, so that applications can be created by users.
3. Knowledge of quantitative methods
4. Problem-solving skills
a systems analyst must be able to understand the problem of a system and design it back so free from the problems that may occur.
5. Communication skills of personnel
this capability useful at the time of interviews, presentations, meetings and preparing reports.
6. Expertise builds relationships between the personnel
this capability is used so that the work environment to be effective.
reference : Jogiyanto, Analisis dan Desain Sistem Informasi, 1991