Elements of System Analysis and Design

System:- A system is an array of components that work together to achieve a common goal by accepting input, processing it, and producing output in an organized manner.

Elements of a System:

The basic three elements of the system are:

  • Input
  • Processing
  • Output
Elements of a System
Elements of a System

In addition of this, four more elements play an important role. These are:

  • Control
  • Feedback
  • Environment
  • Boundaries& Interface

Therefore the key elements of a system are:

  • Output

First of all, we must determine what the objectives or goals are, what we intend to achieve. Once we know our aim, we can try to achieve it in the best possible way.

  • Input

Once we know the output, we can easily determine what the input should be.

  • Processes

Here we come to the details of how the inputs & files are converted into outputs. Processes may modify the input totally or partially depending on the specifications of the output.

  • Control

Control of the system is the decision-maker that controls the activities of accepting input processing and producing output.

For Eg.

In an organizational context, management as a decision making body controls the inflow, handling and outflow of activities that affect the welfare of the business.

  • Feedback

The feedback of the output allows it to be measured against some standards& making adjustments in the processing accordingly.

  • Environment

The environment is the source of external elements that have an effect on the system. In fact, it determines how a system must function.

  • Boundaries & Interfaces

A system should be defined by its boundaries- the limits that identify its components, processes & interrelationships when interfaces with another system.

For Eg.

A teller system in a commercial bank is restricted to the deposits, withdrawals & related activities of customers checking and saving accounts.


Types of Systems

Common classifications are

  1. Open & closed systems
  2. Deterministic & probabilistic systems
  3. Physical or abstract systems
  4. Main Made information systems


Open & Closed Systems

I) An open system is a system that interacts freely with its environment.

II) This type of system can adopt to changing internal & environmental conditions.


Business organization, human being.

I) It has no interaction with its environment.

For Eg.

Computer program which processes predefined input in a predefined way.


Deterministic & Probabilistic Systems

I) The behaviour of a deterministic system


I) Computer Program.

Physical and Abstract systems

Physical systems are tangible or visible systems.

I) Physical systems may operate statically or dynamically.

For Eg.

II) A programmed computer is a dynamic system because data, program& output change as the user’s demand changes.

For Eg.

A model, an algorithm or an equation.

Man- Made Information System

It is generally believed that information reduces uncertainty about a state or event.



Information System

An information system is an organized set of components for collecting, transmitting, storing& processing data in order to deliver information for action.

The major information systems are:-

  1. Formal Information Systems
  2. Informal Information Systems
  3. Computer Based Information Systems


Formal Information Systems

A formal information system is based on the organization represented by the organization chart.

Types of Formal Information System

  1. Strategic Information System
  2. Tactical Information System
  3. Operational Information System


Informal Information Systems

Informal information system is an employee based system designed to meet personnel & vocational needs & to help in the solution of work related problems.

It also directs information upward, through indirect channels. In this way it is considered to e a useful system because it works within the framework of the business & its stated policies.


Computer-Based Information Systems:

Common computer-based information systems are

TPS(Transaction Processing System)

These systems are concerned with carrying out simple but repetitive computations on large number of records like maintenance of inventory records, payroll preparation etc.

MIS(Management Information System)

The system required to obtain tactical information is known as MIS. These system assist lower management in problem-solving & making decision. They use the results of transaction processing & some other information also.

DSS(Decision Support System)

These system assist higher management to make long term decisions. These type of systems handle unstructured or semi structured decision.