The Importance Of Developing An Information System

The Importance Of Developing An Information System

1. Problems existence
the old system problems can not operating as we expected.

2. Organization Growth
organitation growth cause the new system must be arranged to inform that more increasing information.

3. For reach the opportunities
the development of information cause increasing the supply of information with the result can help to decide that done by management.

4. Instructions existence (directives)
the existence instructions from the leader or the outside of organitation, as the government regulation.
for example : employee minimum wages


The Purpose Or Goal Of Developing An Information System

1. Solving the problems that happen in case.

2. Reach the opportunities

3. Complete the directives that given


The Organization’s Expectations After Implementing An Information System

1. Performance
increasing the work of the new system so that it more effective.

2. Information
Increase the quality of information.

3. Economy
Increase the profit and decrease the cost.

4. Control
The Purpose of control is detect and fix the mistakes or error.
exemple : application barcode inside comodity in mini market

5. Efficiency
The organization must to increase the efficiency of operational.

6. Services
Increase the services of system.

The Principles Of Developing An Information System

1. Developed system for the management.
The system is finished develop, so the system must support its necessary by management.

2. Developed system is a big investment
Developing system need much money and modern technologi.

3. The development of system needs educated people.
Human is determine success or fail a certain system.

4. There is a step or process that must be done in system development.
Process developing system is teamwork.

5. System development process must not massage.

6. Don't be afraid to cancel a project.
cancel the project have to accurate opinion.

7. Documentation is important for guidance in system development



System Development Life Cycle Models

a. Model of waterfall explanation :

- Requirement
- Design
- Implementation
- Verification
- Maintenance

b. Model iteratif explanation :

- Initial planning
- Planning,
- Requirement
- Analysis and design
- Implementation
- Deployment
- Testing
- Evaluation

c. Model spiral explanation :

- Determine objectives
- Identify and resolve risk
- Development and test
- Plan the next iteration




Approaches Of Developing A System

1. Classical approach and structured approach ( looked into used methodologies).

a. Classical Approach
Is classic approach methodologies to develop the system by following the step in system life cycle.

b. Structured Approach
User involvement from the beginning to determine the needs of the system


2. Piecemeal approach and system approach (looked into the target to reach).

a. Piecemental Approach
A development of system that tell about only an activities.

b. System Approach
A development of system that attention to all activities in unity form.


3. Bottom-up approach and Top-down approach (looked into the way of determining requirement of system).

a. Bottom-Up Approach
A bottom-up approach is piecing together systems to give rise to grander systems, thus making the original systems sub-systems of the emergent system. In a bottom-up approach the individual base elements of the system are first specified in great detail. These elements are then linked together to form larger subsystems, which then in turn are linked, sometimes in many levels, until a complete top-level system is formed. This strategy often resembles a "seed" model, whereby the beginnings are small but eventually grow in complexity and completeness. However, "organic strategies" may result in a tangle of elements and subsystems, developed in isolation and subject to local optimization as opposed to meeting a global purpose.


b. Top-Down Approach
A top-down approach is essentially breaking down a system to gain insight into its compositional sub-systems. In a top-down approach an overview of the system is first formulated, specifying but not detailing any first-level subsystems. Each subsystem is then refined in yet greater detail, sometimes in many additional subsystem levels, until the entire specification is reduced to base elements. A top-down model is often specified with the assistance of "black boxes" that make it easier to manipulate. However, black boxes may fail to elucidate elementary mechanisms or be detailed enough to realistically validate the model.


4. Total-system approach and modular approach (looked into the way of developing it).

a. Total System Approach
The approach that developed sistem simultaneously.

b. Modular Approach
Solving problem that complicated become simple module.

5. Great loop approach and evolutionary approach (looked into technology to be used).

a. Great Loop Approach
The approach that comprehensive use good technologi because development of technologi cause appear risk.

b. Evolutionary Approach
The application of technologi only for needed applications and can follow the fast development of technologi.


The Meaning Of Methodology, Method And Algorithm


A.Methodology can be defined as:
The unity of methods, procedures, the regulations that is used in science for developing the information system.

B. Method
A way to do something.

C. Algorithm
Algorithm is a sequence of finite instructions, often used for calculation and data processing.



Classifications Of Development Methodology


1. Functional decomposition methodologies
Emphasizing resolving of system becomes subsystem.

Example:
- HIPO (Hierarchy plus Input Process Output)
- SR (Stepwise Refinement)
- ISR (Iterative Stepwise Refinement)
- Information-Hiding


2. Data-oriented methodologies

This methodologies is grouped into 2 class:

A. Data-flow oriented methodologies
- SADT (Structured Analysis and Design Techniques)
- Composite Design
- Structured System analysis and design.
B. Data structure oriented methodologies
- JSD (Jakson's system development)
- W/O (Warnier/ Orr)

3. Prescriptive Methodologies
In this methodology including:
Example:
- ISDOS (Information System Design and Optimization System)
- PLEXSYS
- PRIDE
- SDM/70
- SPECTRUM
- SRES and SREM, etc.


Tools For Developing A System


The tools there are in the form of diagram and chart, such as :
- HIPO diagram.
- Data flow diagram.
- SADT (Structured Analysis and Design Techniques)
- structured chart.
- Jackson's diagrams.

Besides the tools that mention above, there are utilizes that used at all of methodology. The tools as a chart set that grouped by:

- Activity charting: to figuring activity.
example: - chart's substituting.
- flowchart.

Layout charting:to figuring layout.

- Personal relationship charting: to figuring person relationship,
example: - organization chart.
- working distribution chart



Techniques Used In Developing A System

1. Technique Management project
For schedule a project
Example: CPM (Critical Path Method) and PERT (Program Evaluation And Review Technique)

2. Technique find fact
to collect data and determine and find the facts
– interview
– Observation

3. Technique cost analysis

4. Technique run meeting

5. walkthrough


The Differences Of Being A System Analyst And A Programmer.

1. System Analyst
A systems analyst is responsible for researching, planning, coordinating and recommending software and system choices to meet an organization's business requirements. The systems analyst plays a vital role in the systems development process. A successful systems analyst must acquire four skills: analytical, technical, managerial, and interpersonal.

2. Programmer
A Person who make a software in computer and understand about technologi of computer.