GENERAL OVERVIEW DEVELOPMENT SYSTEM

GENERAL OVERVIEW DEVELOPMENT SYSTEM


The need and importance of the development system

Development of a system means preparing for the new system replaces the old system as a whole or improve the existing system.
A system needs to be replaced is because;
The existence of the problems that arise in the system longer.
Irregularity, this can be.
Operating inefficiently.
Not a here to policy management.

The growth of the organization
The growth of the organization's old system is not effective anymore, so have to be developed a new system.

To seize the opportunity
In the competitive market, speed or efficiency of the information is very successful, or not to determine strategies and plans that have been developed to achieve opportunities that exist.

There is instruction.
directive is sometimes the instructions given to the development of the old system or creating a new system, instructions can be derived from the leadership organization.
With the new system developed, the expected increase in-going improvements in the new system. Pieces namely, the

Performance, increased system performance toward be more effective, can be seen through trough put at the number of jobs that can be done in a certain time.

Response time is the average time between two transactions and response time in responding to system problems.
Information, improving the quality of information presented.

Economy, upgrading of benefits or the benefits and cost reduction that occurred.
Control, Improvement of the control-control to overcome and fix errors and cheating, and deception that will occur.

Efficiency, improvement of the efficiency operation, related to the efficiency of how resources are used is used with the minimum of waste. Efficiency can be measured from if output divided by the if input.
Service, the increase of services provided by the system.

The principle of the development system

System that is developed is to management system.
After the system completed the system should be developed can be used by the management and can meet all the needs that are required by management.

System developed is a large capitals investment.

Development of a system require capital funds that are not small, especially with use of current technology. System developed is a large capital investment, should consider the following

All alternative should be investigated.

From some alternative investment should be investigated to determine alternative the best and the most profitable.
Investment should be the best value.
This is the best investment must also be measured. Said the new investment is profitable if the value, which means that the benefits or results that are greater than the cost to obtain it. Cost-benefit analysis or cost-Effectiveness analysis can be used to determine whether the project is worth investing or not

System developed need educated people.
People involved in the development and use of this system should be the people who educated about the problems that exist and to solutions that may be made. Educated mean that not have to follow formal university education, but exercise can be done working (on-the-job training).

Stages of work and tasks that must be made in the process of system development.
Before the system development process is done, it must be made before the schedule of work showing stages workplace and work tasks to be done, so that the process of system development can be conducted and completed in accordance with success time and budget that is planned. Cycle or systems development life cycle (system development life cycle) generally shows the stages and work tasks that must be done.

The process of developing the system does not handle.

The process of developing the system does not have to order.

Stages of development of system on the principle of no
shows the steps that must be done and the steps that must be done not only can this series, but can be done together. For example in the development system, design of output is a phase that must be done before the design file. This does not mean that all output must be designed first all new design file can be done, but can be done simultaneously.
Do not be afraid to cancel the project.

The decision to proceed or cancel a project should be evaluated carefully .. for certain cases, where a project had to be stopped or canceled because it is not feasible anymore, it should be done with the firm.

Documentation must have for the development system.
This documentation can be made at the time of the process of developing the system itself is still in the process, because this documentation can be produced from the work of each step in the development system. Documentation created and collected during the process of system developer can be used for communication between the system analyst with the system and can be used to encourage the involvement of the system.


System development life cycle .

Model secuencial linier
On this model the steps are
Requirements
Starting with the building requirements of all elements of the system and allocating some subset of the software needs to be a engineer.
Design
Design software is a multiple-step process that focuses on the four attributes in the different programs, data structures, software architecture, interface representations, and detail (algorithm) procedural
Implementation
Design should be implemented into the form of program code that can be processed by computer
Verification
Ensure that all functions that can be done by the system running well, at the time the test was conducted to find the mistakes in the program.
Maintenance
Changes in software usually occurs after the use by the user, changes can occur due to adjustments to the outside environment, at the time of this software is needed, for example device antiviruses, virus with the new anti-virus must be able to adjust them.

Iterative model

.This model does not vary much with the waterfall model, different is in this model there is.
Initial planning
The planning, the plan starts with knowing the purpose software engineering, the model is used, and certain about those who participate in making the system.
Planning
Make a schedule activity or rundown of the development system.
In the model this iterative cycle where there is after the implementation of the testing is done when there are errors of evaluation will be done, when there are errors this model allows the re-planning with additional information from the evaluation results and generate a better product, the process continues to progress this cycle performance system to the most good.

Spiral Model.
The process is described as spiral.
a.Each loop represents one phase of the process software will be developed a certain organization.
b.Loop in the most focused on the feasibility of the system, the next loop on the definition of the needs of organizations of the system, the next loop associated with the design of the system will be developed and so each Loop is divided into several sectors.

a. Concept operation
determine the destination of the specified phase. Restrictions on the process and product are known. Planning have been prepared. The risk of the project is known. Alternative strategies have been prepared based on the risks that are known, and already planned.

Development plan.
Development planning system, known at tools that at coupled.
Test plan.
Planning the test conducted to test whether a system of organization is eligible to be used.

System development approach

1. The classical approach vs structured

1.1 Classical Approach
Classical approach is the approach in the development of systems that follow the stages in the life cycle without a system provided with the tools and techniques are adequate. Problems in phenomenological classic.

a. Software development will be difficult
Less classical approach to provide tools in the development of techniques in the system and as a result, the software development process does not become effective and difficult to be done by programming. Case with other approaches that provide structured tools, such as data flow diagrams, data dictionary, decision table, and so forth.

b. Cost of care and maintenance system will be expensive
High cost of treatment in the classical approach is because the documentation system developed less complete and less structured.

c. Possibility of system error
Some research indicates that the system does not at a test during the development phase is the main source of system errors. Classical approach does not provide a way to system analysts, to do testing system, so the possibility of errors the system will become greater.

d. Success of the system less secure
In the classical phenomenological because the system is less involved in the development system, the needs of the system will be less than in accordance with the desired result, and as a system that is applied to be less successful.

Problems in the implementation of the system
Because the system is less involved in the development system, then the system will only recognize the new system at the implementation stage only. as a result of this system will not upset because the new system and become frustrated because it can not operate the system with both

1.2 The structured approach
Structured approach, complete with tools and techniques needed in developing the system, so that the final results of the system will have developed a system with well defined structure and clear.

Through this structured approach, the problems are complex in the organization can be solved and the results from the system will be easy to maintain, flexible, more satisfied users, have a good documentation, on time, according to the budget cost of development, can improve productivity and quality will be more well.

2. The piece approaches vs the system

2.1 The piece
A. approach that emphasizes the application of a particular activity or course
b. on this approach, activities or applications that are selected, developed without considering the overall objectives of the organization.

2.2 The system
• Viewing the system as a whole and the unity form a certain information.
• Emphasizing the achievement of overall objectives

3. Ride-down approach vs. top-down approach

3.1 The bottom-rise (bottom-up)
• Starting from the bottom level of the operational
• It is the characteristics of classical
• Known by the term data-analysis

3.2 The top-down (top-down)
• Starting from the top-level strategy planning
• It is the characteristics of structured
• Also known to the decision-analysis.

4. The system-comprehensive approach vs. modular

4.1 The approach of comprehensive system information
• Develop a system simultaneously and comprehensively, and
• It is characteristic of the classical approach

4.2 The modular approach
• break a complex system into parts of a simple
• System to be developed on time, easy to understand and kept
• It is characteristic of the structured approach

5. The far-jump approach vs. developing

5.1 The jump-distance (great-loop approach)
• Develop a system simultaneously using technologi sophisticated.
High-risk and spend a lot of cost

5.2 The approach evolved (evolutionary approach)
• Applying advanced technology for application-specific applications
• Developed for the needs
• Save the cost and can follow the development of technology

System development methodology.

methodology
- totality methods, procedures, working concepts, rules and postulat used in science, art or discipline the other.
For example the methodology is structured systems analysis and design for use on the development of the system.

method
- One way, systematic techniques to grind
For example is the simplex method to find the value of x and y in the equation linear.

Algorithm
- Sort-order procedure to solve a problem.
For example quick sort algorithm is in the process of sorting

Classification methodology development.
a. Functional decomposition
- Emphasizing breaking into the system so that the subsystem will be more easy to understand, designed and implemented
- Example: Stepwise refinement, iterative stepwise refinement.
b.Data-oriented
- Emphasizing on the characteristics of the data processed

• Data-flow oriented: modules according to the type of data elements and behavior logic in the module system
Example: composite design, SSAD

• Data-oriented structure: emphasis on the structure of input and output in the system, then this structure will be used as a basic structure of the system are made.
Example: Jakson's system development.

Prescriptive
- Usually provided by the manufacturer of the software
Example: PRIDE, Spectrum.

Tool in the development system

Tools used in a methodology as a general picture, diagram or graph, in addition to the equipment that is not the form of graphic image is an example of data dictionary and a form to present data.

Example of system development tool that shaped graph
Data Flow diagrams, structured charts, SADT, Jakson's diagram.

Tools that use the chart-chart:
o Activity charting: describe the activity, flowchart.
o Layout charting: describes the system layout diagram
o Personal relationship charting: describes the relationship of personnel, for example: organization chart.

System development techniques.
a. And management techniques for project scheduling, for example: CPM.
b. Techniques to find, collect and define data / facts
- Interview
- Observation
- Questioner.
c. Technical operating cost / benefits, for example, cost-benefit and cost-Effectiveness analysis.
d. Technical meeting to run a membership organization.
e. A system of technical inspection organization.

System analyst and programmer
System analyst
learn the issues and determine the needs of the system to identify a solution.
And the task of responsibility
Not only on the making of an application program or computer, but in the system as a whole.
Knowledge must be knowledgeable, not only on the technology, but also in the field of application systems that handling.
laborer systems analyst in making the program is limited to solving the line of the system.
System analyst jobs involving contact with many people in analyst system.

Programmers
writing program code based on the design of the system will be made by analysts
Duties and responsibilities
- Limited in making program
- The programming is limited to computer technology, computer systems, utilities and language program is required.
- Employment is the technical and programming must be precise in making the instruction program.
- Employment not the relationship with people.

System analyst duty bridge the knowledge gap that occurs between the user and programmer system itself

Analysts knowledge required system.
. Technology, data processing, and computer programming.
. Business knowledge is broad and general.
. Quantitative methods: linear programming.
. Expertise breaking a problem.
. Communication between the expertise of personal.
. Expertise builds relationships between the personal.



reference :
1. Structured Analysis &Design of Information System, Aktas, A.Ziya.Prentice-Hall, 1987
2.Structured System Analysis ; Tools and Techniques,Chris Gane and Trish Sarson.Prentice-Hall, 1979
3.System Analysis and Design A Structured Approach, William S.Davis.Massachusetts: Addison-Wesley, 1983
4.Information Systems Theory and Practice, John Burch, Gary Grudnitski, Fourth Edition;New York: John Wiley & Sons,1986