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

Basic Concept of Information Systems Analysis and Design

There are two approaching to definition of system:

1. Definition of system based on approach of procedure
According to this approach, system interpreted by as a working network from procedures which is interaction and work along to finish a specific-purpose or goal. A procedure is a correct sequences of instruction steps explaining what have to be done, who have to do, when have to be done and how to do that.

2. Definition of system based on approach of element

According to this approach the definition of system is a set of elements which is have interaction to reach specific-purpose or goal.

Characteristic system

Characteristic a system can be explained as follows:

1. Components
Consist of a number of components which interact, what each other working along to form an unity. The example is Supra System that is a larger ones system.

2. Boundary
A system has a boundary to limiting system with environmental or other system outside its.

3. Environments
Environment is a media link between a subsystem with other subsystem.

4.Interfaces
Interfaces represent link media between one subsystem with other subsystem. Passing this link enable the source of resource emit a stream of from one sub system to other sub system.

5. Input
Entered energy into system can in the form of treatment input and signal input. The treatment input is entered energy system to can walk. While signal input is energy which in process to yield output.

6. Output
The result from processed energy and classified is become an output which good for and rest of dismissal.

7. Process
Process is the change an input become output.

8. Objective/goal
A system sure have field goal or objectives. If system don't have target hence system operation there will be no use.

The Classification Of System

a. Physical system
System abstract is which in the form of idea or idea which not see itsly it system teologia.

b. Abstract system
System physical represent existing system physically, for example computer system.

c. Deterministic System

The Certain system operate with behaviour which have earned can be predicted, interaction between its sharess can be detected categorically so that its output can be forecasted. for example : Computer programe, executing precisely as according to its instruction network. System of pay, and others.

d. Probabilistic System
The System which is input and its process can be defined, but yielded output cannot be determined categorically; always there is a little mistake / deviation to forecast of the way system. for Example : marketing system.

e. Open System
The system that relation and effect external environment .This system accept input and yield output for external environment / the other sub system, so that have good operation system. This system tend to measure up to adaptation, can adapt to its environment so that can continue its.

f. Closed System
The System Physical where the process that happened do not experience of transfer of items, information or energy with environment outside system. This system work automatically without existence of interfere in of external side of it.

g. Relatively Closed System
The closed System but doesn't closed at all to accept other influences. This system in its operation can accept influence from outside which have been defined in certain boundarys.

h. Artificial System
The System imitating occurence in system. This system is formed pursuant to occurence in nature where human being unable to do it. Equally imitat exist in nature.

i. Natural System
The natural System is occurence in nature. for Example of : sea, solar system and others.

j. Human made system
Human made system is system which condition of its dicey future because containing probability element.

Information
Data is fact. Information is data that processed become better form and more meaning to accept it. If data is not useful to accept it so the data cannot be referred as by information.

Information Cycle
Data represent form which still raw which not yet earned to tell a story many, so that need processing is furthermore. Data processed to pass a model to yielded information. Data processed to yield information use certain process model.
Processed data pass a model become information, receiver later then accept the information, making a decision and conduct action, meaning to yield the other action to make a number of data return. The data will be arrested as input, in process return to pass a model and so on form a cycle.

Quality Of Information
Quality of information depended from three things, that is ;

1.Accurate
Accurate meaning information have to free from mistakes and cannot or mislead. Accurate mean information be clear express its intention.

2.Timeliness
Timeliness meaning incoming information receiver may not lose time.

3.Relevance
Information have benefit for its user.