SYSTEM DEVELOPMENT LIFE CYCLE

(SDLC)

MANAGEMENT INFORMATION SYSTEM

Introduction

The system development life cycle (SDLC) is the

traditional system development method used by

most organizations. “The period of time begins

when a system is conceived and ends when a

system is fully operational for use and gets

maintained is called the development life cycle

of a system.” The SDLC is a structured

framework that consist of sequential process by

which information system are developed.

In the past, developers used the

‘waterfall’ approach to the SDLC, in which

task in one stage were completed before the

work proceeded to the next stage. Today,

developers go back and forth among the

stages as necessary.

SDLC consist the following phases

1. Initial Investigation

2. Feasibility Study

3. System Analysis

4. System Design

5. System Coding

6. Testing

7. Implementation

8. Maintenance

SystemAnalysis

System design

Testing

Initial investigation

Maintenance

Implementation

System Coding

PHASE-IPHASE-III

PHASE-IV

PHASE-V

PHASE-VIPHASE-VII

PHASE-VIII

Feasibility study

PHASE- II

Preliminary Investigation

This phase is very important as in this phase

system analyst identify the real problem of the

existing system, without clear understanding of

the problem in the system, any further work done

will lead to wastage of efforts at a later stage.

Problem definition defines the user requirements,

or what user expect from the system.

This phases also sets the projects boundaries,

which defines what parts of the system can be

changes by the project and what part should

remain unchanged. This also include a rough

idea of the resources requirements, estimated

start and completion dates for each phases and

the number of persons expected to be involved in

each phase for project.

Feasibility Study

A feasibility study is undertaken to determine the

possibilities of either improving the existing

system or develop a completely new system.

This study also help to obtain an overview of the

problem and to get rough assessment of whether

feasible solution exist or not. “Feasibility studies

are used as a basis for deciding whether to

proceed with, postpone or cancel the project”.

There are three aspects of feasibility study as

follows:

1. Technical feasibility = (Analyze of present

technology + Recognition of improvement +

finance consideration)

2. Economical feasibility = (Benefits + Savings

are compared with the cost)

3. Operational feasibility = Working of System

System Analysis

The analysis phases is the detailed understanding

of all important facts of the business area under

investigation. In this the relationship of the

various system components among themselves

and with environment are studied and

understood. This requires data collection from a

variety of sources. For this, questionnaires,

forms, interviews, study of existing documents,

records etc. are used.

The analyst must try to answer the following set

of questions:

1. What is being done in the organizations?

2. How it is being done?

3. What are the problem arise, how will it be

solved?

4. If a problem arise, how will it be solved?

System Design

The most creative and challenging phase of system

development life cycle is system design. each

module after successful completion of system

analysis, the system is designed. In system

design phase, first the system is broken down

into different module and then its each module is

designed. Design of system is largely the logical

design. The logical design can be sketched on a

paper or on a computer terminal.

The design also including the physical design

element, describe the data to be inputted, the

process involved in the manipulation of data and

the output.

1. The analyst should specify the file structures,

storage devices etc.

2. The database is also designed in this phases.

3. Input, output, files and procedures are planned.

System coding

The next phase is concerned with translating the

system design specification developed. When the

design is accepted by the requested department,

the analyst begins developing the software using

programming language. This is the phase when

the programmer plays their role in development

of the system. They start designing data

structures and writing of programs as per the

documents prepared during design phase.

System Testing

Testing is the most vital phase of SDLC. Once the

system is designed it should be tested for validity. In

this phase, the system as a whole is tested with

different techniques to ensure that the system is bug

free. Although, during design, the programmers test

their programs but this sort of testing is generally

unrecognized without preparation of test data.

During testing phase, the testing is done in

systematic way in order to ensure the reliability of

the system and to make it error free.

Implementation

Implementation is the final phase of development.

After testing, the system is installed at the user’s

place and implemented. It consist of installing

hardware, programs, collecting data and

organizing people to interact with and run the

system. In the implementation phase, user

actually starts using the system. This phase also

involves training the users for using the system.

Implementation can be done in two ways. One

way is by implementing the new system along

with the old system and make them run in

parallel. The other method is to replace the entire

system. In large organizations, the new system

can be implemented in certain areas as a pilot

project and if satisfactory result are obtained, it

can be implemented to other areas also.

Maintenance

Maintenance is the process of incorporating changes in

the implemented existing system for proper utilization.

This involve enhancement, adaptation and corrections.

Enhancement: Enhancement implies adding new

functions or additional capabilities to the system.

Adoption: Adoption implies customizing the software

to run in the new environment

Correction: Correction implies correcting the bugs in

the existing software.