Information System Analysis and Design

The approach of base concept of system

There are two approaches to define the system itself.

1. Procedure Approach

System is a work of network from procedures which is having a mutual connection and together to do the activity or to finish a certain target. (Taken from fundamental of system analysis).
Definition of procedure is the correct sequence from a number instruction which is to explain what must doing, who is done it, when it done and how we done it.

2. Element Approach

System is interacted a group of elements to achieve a certain goal.

Both of definition about system above is right because the definition of system is important role for studying about system definition approach. The approach of system is a group of elements or components or subsystem is a general definition of system itself.

For example:

The company information system is consisting of several subsystems there are inventory subsystem, accounting subsystem, marketing subsystem and etc.

The purpose of system

System has a certain purpose there is:

The purpose of system is to achieve a goal.
For Example: for business system, goals are correctly of purpose for the system.

The purpose of system is to achieve an objection.
For Example: the accounting system and other subsystem from business system, an objection is correctly of purpose for the system.

The characteristic of the system

- Components of system
An integrated a set of components for collecting, storing and communicating information.

- Boundary of system
Boundary of system is scope area between another system and environment.

- Environment
Environment means is everything outside the system boundary.

- Interface
Link between subsystems to another subsystem

- input
Input means all of resources that entered into the system

- output
Output means result of input have been processed.

- Processing
A process from input to be output

- Goal
It’s functioning because there are limits to what it can do and how it can achieve its purpose within its environment


The Classification of system

The Classification of system from several viewpoints such as:

1. Classification of system as abstract system and physical system
2. Classification of system as natural system and human made system
3. Classification of system as deterministic system and probabilistic system
4. Classification of system as close system and open system

Base concept of information

The information is useful for system itself to avoid entropy processing or negative entropy (negentropy). The Information as a concept has a diversity of meanings, from everyday usage to technical settings. Resources of information are data. Data refer to a collection of facts usually collected as the result of experience, observation or experiment, or processes within a computer system, or a set of premises. Data are often viewed as a lowest level of abstraction from which information and knowledge are derived.
Example of information is marketing report from salesmen is useful for management to determine the bonus.


Quality of information

The quality of information

- Accurate is measured by comparing the data to actual events .Payroll information must be exact or accurate. For example the information must be simple, not confusing and true free from mistakes.

- Timeliness
The information likes real time system. Its means that the information comes to user can not be late.

- Relevance
It means the information must have advantages and useful for users.
Information is relevant if it leads to improved decision making. It might also be relevant if it reaffirms a previous decision.

Value of information is depending on 2 factor, advantages and cost.
An information has a high value if the advantages more effective than the cost to get it