Importance of developing an information system

Importance of developing an information system

problems

By using the information system of the problems that usually can be completed with the old manual way with the information system problem is resolved more quickly. For example in the mini market, there is a cashier who has to record transactions a day with the usual manual may be slow but the results, using the information system can be done more quickly.

Irregularity in the growth of System Organization

In an organization there are certain data that must be processed, when organisai is growing data that diolahpun needed so that the larger a system is good, if not use the information system so that both orgnisasi growth will be hampered

opportunities

System information also assists in achieving opportunities. And also make it easier to seize opportunities.

directives

Informs the system can more quickly provide instruction, for example, the confusion are a company looking for a document, then the system with the information we provide live instruction to the system to search for it.

Destination development system

Development means the system can arrange a new system to replace the old system as a whole or improve the existing system. The old system need to be replaced or repaired is because some things, are as follows:

• The existence of the problems that arise in the old system. The problems that arise can be:

a. Irregularity

Irregularity in the old system caused the old system can’t operate in accordance with that expected. This irregularity may be operating inefficiently.

b. The growth of the organization

Growth of the organization must be the establishment of a new system. The growth of these organizations is the information needs of the area, the volume of data increases, changes in the new accounting principles.

• To seize opportunities

Organization began to feel that information technology should be used to improve the provision of information so that it can support in the decision making process that will be done by management. In the competitive market, speed or efficiency of the information isn’t to determine the success or strtegi plan and that plan has been developed to reach the opportunities that exist. If competitors can utilize, while the company can ‘t take advantage of this technology, the kesempatankesempatan will fall ketangan competitors.

• The instructions

Preparation of the new system can also occur because of instructions from the top leadership or from outside organizations, such as government regulations.

Expected on the new system

Has been developed with the new system, the expected increase will occur, the increase in the new system.

• Performance

Improvement of the performance of the new system which will be most effective. Performance can be measured from the throughput and response time.

• Information

Improving the quality of information presented.

• Economy

Improvement of the benefits or the benefits or a decrease in the cost-reduction.

• Control

Detect and fix errors that occur and will occur.

• Efficiency

Improvement of operational efficiency.

• Services

Improvement of the services provided by the system.

The principle of the development system

When you do the system development process, several principles must not be forgotten. These principles are as following:

• System developed for the management

After the system finished developed, which will then use information from this system is the management, so that the system must be able to support the needs that are required by management.

• The system developed is a large capital investment

System that you will develop the funds that weren’t a little. So every investment capital should consider the following 2:

a. Investigate all alternatives (minimize cost of lost opportunity)

b. Investigation must be best value: cost-benefit analysis & cost-effectivenes analysis

• System that educated people need to be developed

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 here should not mean a formal, but it can be done in the exercise work.

• Stages and work tasks that must be made in the process of system development

System development process generally involves several stages and involves the work of personnel in some form of team for it. Experience shows, without the planning and coordination work that well, then the system development process will not be successful with satisfactory.

• The development of the system doesn’t have to order

The steps that must be done doesn’t need to order, but it can be done together. For example, in the development of the system, design the output stage should be done before the design file. This does not mean that all output must be designed before they can make a new design file. But can be done simultaneously, the output during the design process is still conducted, the results of the output that has been completed can be used to design files.

• Don’t be afraid to cancel the project

For the cases a, where a project had to be stopped or canceled because it is not feasible anymore, it should be done with the firm.

• Documentation system

This documentation should be made at the time of the process of developing the system itself is still in the process. Because of this documentation can be produced from the work of each step in the development system. Documentation created and collected during the process of system development 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

Waterfall Model

Contains a series of activities such as the process has been described above and presented in a separate process, such as the requirement specification, design implementation software, testing . After each step is defined, this step in the sign off and followed the development in the next step.

The steps that are important in this model is

• The analysis and specification

Services, goals and constraints resulting from consultation with users system. Then everything is made in the form that can be understood by users and staff developers.

• Design systems and software

Divide the system design process needs to be system software or hardware. The process produces an overall system architecture. Design software, including the functions of system software that may be in the form of the transformation in one or more programs that can be run.

• Implementation and unit testing

During this stage, the design software we realize as a complete program or program unit. Test units, including units that each test according to specification.

• Integration and system testing

Unit tested and integrated the program into a complete system for menyakinkan that software requirements have been met. After testing, the system was delivered to the customer.

• Operation and maintenance

This phase is long. System installed and used. Maintenance, including correction of errors not found in the previous step. Improvements to the implementation of the system and increasing service needs of the new system as found.

Iteratif Model

Step-step model Iteratif

1. Initial planning

Starting from the initial planning.

2. Planning
This stage, the stages where the plan is structured in such a way to get a system that both the good and the output

3. Requirements
Analyze user needs and the needs of the system

4. Analysis and design
In this process is conducted to analyze the process of the system will be developed and began to design the system.

5. Implementation
In this process is the system that has been created.

6. Testing
At this stage, the system will try to test, to see if in conformity with the desire.

7. Evaluation
This phase will be done from the system evaluation have been made.

Spiral model

Spiral model describes the process as a spiral which is divided into a 4 quadrant:
Processes are beriterasi according to a cycle using a prototyping approach.

• Planning
Namely the duties to plan, gather for the alternative system that will have • Risk Analysis
is to evaluate the alternatives based on the objectives and constraints. Included here to identify the risks and pastian • Engineering
That is a task that is required to build one or more representations of apikasi it. • Cusomer Evaluation.
Re-evaluate the system that was created with the customer

System development approach

• A structured approach versus classical approach (seen from the methodology used)
• Piecemeal approach versus system approach (seen from the target to be achieved)
• The bottom-up approach versus top-down approach (seen from how to determine the needs of the system)
• Total-system approach versus modular approach (seen from the way the developing)
• Great loop- approach versus evolutionary approach approach (seen from the technology that will be used)

A structured approach versus classical opponent approach

Classical approach

• Stages in SDLC-stage
• Not to include users, system analysts put more emphasis
• The problem: the development of hard, expensive treatment, the possibility of error, success is less assured, the problems in the implementation of

Structured approach

• User involvement from the beginning to determine the needs of the system
• Using tools-tools such as data flow diagrams

Piecemeal approach versus system approach

Piecemeal approach

• Emphasizing on an application or event
• Don’t override the overall target

System approach

• Viewing the system as a whole is unity
• Emphasizing the achievement of overall objectives

Bottom-up approach versus top-down approach

Bottom-up approach

• Starting from the bottom level of the operational
• It is the characteristics of classical
• Known by the term data-analysis

Top-down approach

• Starting from the top-level strategy planning
• It is the characteristics of structured
• Also known to the decision-analysis

Total-system approach versus modular approach

Total-system approach

• Develop a system simultaneously and comprehensively
• It is the characteristics of classical approach

Modular approach

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

Great loop- approach versus evolutionary approach approach

great-loop approach approach

• Develop a system simultaneously using the advanced technology
• At risk and spend a lot of high cost

evolutionary approach approach

• Applying advanced technology for application-specific applications
• Developed for the needs
• Save the cost and can follow the development of technology

methodology, method and algorithm

• Methodology

Is methods used in science

• method

A systematic way to grind

• algorithm

Sort-order the procedure to solve a problem

Classification of development methodology

• Functional decomposition

– Emphasizing the breakthrough system subsystem

– Example : HIPO, Stepwise refinement, iterative stepwise refinement, information hiding

• Data-oriented

– Emphasizing on the characteristics of the data processed

• Data-flow oriented: modules according to the type of data elements

• Data-structure oriented: structure of the input and output

• Prescriptive

– Usually provided by the manufacturer of the software

Tool for developing a system

• shaped graph: HIPO, SADT, Jackson’s diagram, etc.

• Tools that use the chart:

ü Activity charting : describes the activity, for example: Gant chart, flowchart, etc.

ü Layout charting: Describes the layout

ü Personal relationship charting: describes the relationship of personnel, for example: organization charts, work distribution chart

Techniques used in the development a system

• Technical project management

Technique that is used to penjadualan project, for example : CPM dan PERT

• Fack finding technique

to collect data and determine and find the facts

– interview

– Observation

• cost-benefit or cost-effectiveness analysis

• Technical meetings run

• walkthrough

System analyst & programmer

• Analyst system: study of the problems and determine the needs of the system to identify solutions.

• programmers: write a program code based on the building design is created by the analyst.

• Analysts duty system bridge the knowledge gap that occurs between the user and system programmers.

Knowledge that is required

• Technology data processing, computer programming and
• Knowledge of general business
• quantitative methods: regression, linier programming, etc.
• problem-solving expertise
• Skills of communication between personnel
• Expertise foster relationships between personnel

References

http://en.wikipedia.org/wiki/Waterfall_model

http://en.wikipedia.org/wiki/Spiral_model