The Importance Of System DevelopmentSystem development can mean to composed a system bew to replace system old ones as a whole or repair system that there. A system necessary developed and repaired, matters that causes system necessary developed, that is:
1. That troubleshoots existence at old ones system. That troubleshoot can be in the form of:
a. Problem.
The problem in this system can be in the form of deceits that causes not wealth treasure the safe companies and truth from data is less well guaranted, errors not intentional that causes data truth not well guaranted, the operation not efficient, and not bidding the management policy that applied.
b. Organization Growth.
Organization growth here that is information need more vaster, data processing volume more increase, bew accountancy principle change. Caused by this change, so old ones system not effective again, so that must there development towards system.
2. To reaches to chances.
Organization will begin to feel that this information technology necessary is used to increase the available of information so that can support in course of decision making that be done. In rivalry, information speed or time efficiency very determine success or not it strategy and plan that have been arranged to reaches to chances existing. Chances this can be in the form of market opportunities, increase the service to customer and other as it.
3. Instructions existence (directives).
Also can happen caused by instructions from higher and or.
The purpose of developing a information systemCaused by troubleshoot likes on, so system development is wanted to break existing troubleshoots, reaches to chances existing and fulfil instruction that given.
Supposed enhanceds in bew system development, that is:
1. Performance, enhanced towards performance system bew so that be effectiveer. The performance measurable from job total that can be done at the time of certain (troughput) and average time that delay between two transactions (response time). For example, before now a only can do a job in certain range of time, but along with age development, so that thing becoming not effective so that emerge willing to increase performance from system so that can do job more than one in certain range of time.
2. Information, enhanced towards information quality that presented. For example, with enhanced existence toward system, so a system before now has information inaccurate is a system that has information with far quality better with willing existence from admin to increase quality so that system be better.
3. Economy, enhanced towards benefits or profits or decreasing cost that. For example, a company use resource very much so that need cost and big investment to run system in companies. With case existence, so here be feeled to develop system so that system experience enhanced so that can depress cost that must be taked.
4. Control, enhanced towards control to detect and repair errors with deceits that. For example, a company has a big error when do a certain process, this evoke a problem when does process done continually. Therefore, here control toward system so that increased so that problem doesn't disturb work from the company.
5. Efficiency, enhanced towards information efficiency. Efficiency here relate to resource that used so that resource that use minimum may be. For example, here a company to use a ancient system for the marketing problem, that is by using sales. Here need enhanced toward system development so that resource that used (sales) minimum may be to depress expenditure by make a on-line system to market product companies.
6. Services, enhanced towards service that given by system. For axample, here a company has a system service manual by using labour. At one time, there are many customer, so that labour here in a dither to serve customer and customer even also felt not pleasant with the mentioned. Need development toward system that use so that customer felt pleasant with service that given. Here company can use system service that can serve customer swiftly and accurate.
System Development Principle System development principles:
1. System that developed management.
2. System that developed big capital investment.
3. System that developed to need one who educated.
4. Work stage and duties that must be done in course of system development (System Development Life Cycle).
5. System development process must not massage.
6. Don't be afraid cancel project.
7. Documentation existence for guide in system development.
System Development Life CycleWaterfall Model
Waterfall Model explanation:1.
Requirement, in process requirement this is systems analysis does need collecting process from customer and or top management either from aspect area also business strategy, towards system and or desirable application.
2. Design, in this stage us does systems analysis process, fitur that need, need from application that be made good to also the application. Beside that, here we also begin to make design plan from system, like interfaces delegation, the data structure, the architecture, and as it.
3. Implementation, implementation process has been continuation from where did we begin to implementation design that made to into program codes that be read by engine language.
4. Verification, process verification here same like testing process towards system and or application that made. This process focus in internal logic from application that made, as certain that any line coding checking. Beside that here we also have done testing process towards possibility towards errors from system that made.
5. Maintenance, process maintenance here be repair process and maintenance towards system that made. Repair process here done when application and or system that made to experience error after to customer so that must necessary repair process towards system and or caused by development towards an OS so that application must be repaired again to be update.
Iteratif Model
Iteratif model explanation: Iteratif Model here same with waterfall model, here found same processes, like requirement, design, implementation, and testing (verification).
1. Initial planning, be beginning planning process and or beginning ideas to make a system.
2. Planning, planning here be a thinking that ripe towards system that be made.
3. Requirement, same like in process requirement waterfall model, here systems analysis does need collecting process from customer and or management on towards system and or desirable application.
4. Analysis and design, in this stage us does systems analysis process, fitur everything that need, need from application that be made good to also the application. Beside that, here we also begin to make design plan from system, like interfaces delegation, the data structure, the architecture, and as it.
5. Implementation, implementation process has been continuation from where did we begin to implementation the design that made to into program codes that be read by engine language.
6. Deployment, process deployment here purpose has been distribution process towards system that made, in our meaning distributes before hand system to society before do testing so that we know our system deficit.
7. Testing, process testing here we have done testing towards system and or application that made. This process focus in internal logic from application that made, ascertain that any line coding checking. Beside that here we also have done testing process towards possibility towards errors from system that made.
8. Evaluation, process evaluation here be repair process, maintenance and renewal towards system that made. Repair process here done when application and or system that made to experience error after to customer so that must necessary repair process towards system. Maintenance process and renewal be done caused by development towards an OS so that application must be repaired again to update. In renewal process here will return to do process planning, data collecting (requirement), analysis system and design, implementation, deployment, testing and return again to evaluation. if there development again, so this cycle be repeated again.
Spiral Model
Spiral model explanation:Spiral model is divided to be 4 task areas, that is:
1. Determine objectives, in this process us will determine what will be made system, either from also output from it system.
2. Identify and resolve risk, here we do identification process, planning and analyze risks may be happen. In identification process and planning, we must define before hand resource, time precision, and other related information project with system that we shall make. While in risk analysis process here we do analysis towards risks may be happen, between management or technical.
3. Development and test, in process development and test this is us do engineering process, construction and testing towards system that be made. In engineering process and construction, we do process coding to make a application. While in testing, we do testing process towards system or application that we have made.
4. Plan the next iteration, here we do iteration process for plan next and or evaluation in the event of request from customer in order to change towards system or application.
In this spiral model, when is process revolutionary begun, system engineer team moves clockwise surround spiral begun from the kernel. Spiral rotation first track produces development from product spesification. Spiral rotation furthermore may be worn to develop a prototype, and progressively develop system version will be increase. Each track that pass planning region produces to setting in project plan.
Approach System Development Found several approach to develop system, that is:
1. Classical approach vs structured approach (looked at from methodology that used).
2. Piecemeal approach vs system approach (looked at from target that be achieved).
3. Bottom-Up approach vs Top-Down approach (looked at from manner determines need from system).
4. Total-system approach vs modular approach (looked at from manner develop it).
5. Great loop approach vs evolutionary approach (looked at from technology that used).
1. Classical Approach Vs Structured Approach
Classical ApproachClassical approach is approach insides system development that follow stages at system life cycle without supplied with tools and techniques.
Troubleshoots that can emerge from approach classic, that is:
1. Software development will be difficult.
Classical approach less give tools and techniques insides develop system and as finally software development process becoming not directional and difficult to done by programmer.
2. Treatment cost or system maintenance will be more expensive.
The expensive treatment cost at classical approach caused system documentation that developed less complete and less structured.
3. Big error possibility system.
System not test during the development stage is principal source from system errors. Classical approach doesn't prepare to manner systems analysis to do testing system, so that system errors possibility will be bigger.
4. System success less well guaranted.
Emphasis from classical approach work from system developers staffs, not in system user. Because classical approach less involve system user in system development, so system user needs are less matching with the one which desirable and as finally system that applied less success.
5. System applications internal issue.
Because system user involvement under communication in system development stage, so only will know only in stage will applied. As finally system user will be startled and unaccustomed with bew system suddenly introduced.
Structured ApproachStructured approach equiped with tools and techniques that wanted in system development, so that end result from system that developed be got system the structure will be defined well and clear.
2.Piecemeal Approach Vs System Approach
Piecemeal approachPiecemeal approach be to system approach development that emphasized at one particular activity or certain application. Activity that chosen, developed regardless of the position at information system or regardless of overall target from organization.
System approachSystem approach pays information system as one integration unitary to each activity or the application. This approach also emphasized in overall goal achievement from organization, not only in that information target.
3. Bottom-Up Approach vs Top-Down Approach
Bottom-Up ApproachThis approach begun from level under organization, that is begun from needs formulation to handle transaction and climb level on with formulate information need based on transaction. This approach also be feature classical approaches. Bottom-up approach is used in systems analysis stage is called also with data analysis, because that be pressure data that be cultivated before hand, information that be produced to follow to follow the data.
Top-Down ApproachThis approach on the contrary begun from level on organization, that is begun with define target and organization policy. Step furthermore from this approach melakukannya information need analysis. After information is determined, so process goes to transaction processing, that is determination output, input, data base, operating procedure and control. This approach be feature from structured approach. Top-down approach when used in systems analysis stage called also with term desicion analysis, because that be pressure information that wanted for decision making by management beforehand, then data necessary cultivated to defined to follow information that wanted.
4. Total-System Approach vs Modular Approach
Total-System ApproachTotal-system approach to be approach develop system together according to comprehensive. This approach less synchronized for complex system, because will be difficult be developed. This approach be feature classic approaches.
Modular ApproachThis approach try to divide complex system to simple some part, so that system easier will be understood and developed. Furthermore consequence system can be developed bick of time that planned, easy understood by system user and easy to maintained. This approach be feature structured approaches.
5. Great-Loop Approach vs Evolutionary Approaches
Great-Loop ApproachThis approach apply change comprehensive according to together use sophisticated technology. This change contains many risks, because computer technology so great-loop. This approach also too expensive, because need investment at the same moment for all technology that used and difficult to developed because too complex.
Evolutionary ApproachThis approach apply sophisticated technology just for applications that need that moment and then be developed for periods next based on technology development. This approach causes investment not too expensive and can follow fast technology development.
System Development Methodology Methodology is methods unitary, procedures, job concepts, rules and postulates that used by a science, art or discipline the other. Method is a manner, systematic technique to does a certain. System development methodology means methods, procedures, job concepts, rules and postulates that be used to will develop information system. Algorithm is sequence procedure to break a problem.
Classification based on existing methodology can classified to be three, that is:
1. Functional decomposition methodologies.
This methodology emphasizeds in solution from system into subsystems smaller, so that easier to be understood, designed and applied. Belong this methodology, that is:
HIPO (Hierarchy plus Input-Proccess-Output)
Stepwise Refinement (SR) or Iterative Stepwise Refinement (ISR)
Information-hidding
2. Data-oriented methodologies.
This methodology will emphasized in characteristics from data that be processed. This methodology can be grouped to into two class, that is:
a. Data-flow oriented methodologies.
This methodology is based in solution from system intoes modules based on data element type and module logic behaviour insides system. Belong in this methodology, that is:
SADT (Structured Analysis and Design Techniques)
Composite design
Structured System Analysis and Design (SSAD)
b. Data structure oriented methodologies.
This methodology emphasizeds structure from input and output at system. Belong this methodology, that is:
JSD (Jakson's System Development)
W/O (Winner/Orr)
3. Prescriptive methodologies.
This methodology is usually is provided by software maker factory. Belong in this methodology, that is:
ISDOS (Information System Design and Optimization System)
PLEXSYS
PRIDE
SDM/70
SPECTRUM
SRES and SREM
Chapin's approach
DBO
PAD
HOS
MSR
PDL
Tool In System Development Tools that used in a methodology usually shaped a picture or diagram or graph. Graph formed system development tools, that is:
HIPO diagram
Data flow diagram
Structured chart
SADT diagram
Warnier/Orr
Beside graph formed tools, found several graph formed tools has general likes Chart. Chart can classified as follows:
1. Chart to describe activity (activity charting).
System flowchart
Program flowchart that can be in the form of:
Program logic flowchart
Detailed computer program flowchart
Paperwork flowchart or form flowchart
Database relationship flowchart
Process flowchart
Gantt chart
2. Layout charting
3. Staff relatioanship charting
Working distribution chart
Organization chart
Technique In System Development Techniques that can be used in development system, that is:
1. Project management technique, that is CPM (Critical Path Method) and pert (program evaluation and review technique). This technique is used for project scheduling.
2. Fact finding techniques, that is technique that can be used to gather data and find facts in study existing system, that is:
Interview
Observation
Questionnaire
Sample collecting
3. Cost-effectiveness analysis or cost benefit analysis
4. Technique to run meeting
5. Technique inspection/walkthrough.
Analysis System And ProgrammerAnalysis system is one who analyze system to study and identify that problems and determine user needs system.
Programmer is one who write program code to a certain application based on has planned to get up that made by system analyst.
Function and or task from a analyst system that is as mediator or liaison between system user with programmer. Analyst system must realize right second knowledge differ about the computer technology to can communicate with programmer and knowledge about application that be developed so that can communicate with system user.
Knowledge And Skill That Need System AnalystFound several vast eruditions and skill that must has by a system analyst, that is:
1. Knowledge and skill about data processing technique, computer technology and computer programming.
Technical skill that must has belong skill in tool use and technique for application software development with skill in use computer.
Technical knowledge that must has cover erudition about hardware, data communication technology, computer languages, os, utilities, and another.
2. Knowledge about business in general.
This knowledge be wanted so that system analyst can communicate with system user.
3. Knowledge about quantitative method.
System analyst use many quantitative methods in build application models, like dynamic programming, regresion, network, decision tree, trend, simulation and other as it.
4. Trouble-shooting skill.
System analyst must has ability to put complex troubleshoots that is faced by business, divide problem into parts, analyze it and then must can return composed to be a system can overcome troubleshoots.
5. Communication skill delivers staff.
System analyst must has ability to hold communication either through tongue or article. This skill is need in interview, presentation, meeting and report maker.
6. Skill builds connection delivers staff.
Human is factor critical insides system and human character one with another differ, so that need a skill to build connection delivers staff.
LIBRARYHM, Jogiyanto. Analisis & Desain Sistem Informasi. Yogyakarta: ANDI,2007.
Roger S. Pressman, Ph.D., Rekayasa Perangkat Lunak, Buku Satu.Yogyakarta: ANDI.
