SDLC

1. System Development Life Cycle: - A System development life cycle is a framework consisting of
many stages. Each stage has its own key questions and importance. Either we can improve the
existing system or create new system. We have to perform all the stages step by step. System analysis
and design are the key stages of system life cycle. In system engineering, information system and
software engineering, is the process of creating or altering the system, and it contains models and
methodologies that analyst use to develop these systems.
Systems Development Life Cycle (SDLC) is a process used by which asystems analyst can develop
an information system, includingrequirements, validation, training, and user (stakeholder)
ownership. Inproject management, a project can be defined both with a project life cycle (PLC) and an
SDLC. According to Taylor (2004) "the project life cycle encompasses all the activities of the project,
while the systems development life cycle focuses on realizing the product requirements".
It is also called system study. The system analyst gives a system development project meaning and
direction with the help of SDLC.
The stages of system development life cycle are given below: -
1. Recognition of Needs.
2. Feasibility Study.
3. Analysis.
4. Design.
5. Implementation.
6. Post-Implementation and Maintenance.
Recognition of Needs
One must know what the problem is before it can be solved. The basis of candidate system is
recognition of need for improving the system. The key question is:
What is the problem?
This recognition of need leads to a preliminary survey or an initial investigation of current system to
determine whether an alternative system can solve the problem. If the problem is serious enough,
management may have an analyst look at it.
The idea for change may originate in the environment or within the firm. Environment-based ideas
originate from customers, vendors, government sources etc. When investigated each of these ideas
may lead to a problem definition. Idea for change may also come from within the organization –
top management, the user, the analyst. User-originated ideas also prompt initial investigation.
Feasibility Study
Depending upon the results of the initial investigation, the survey is expanded to a more detailed
feasibility study. A feasibility study is a test of a system proposal according to its workability, impact
on the organization, ability to meet user needs and effective use of resources. The key questions are:-

2. 1. What are the user’s demonstrable needs and how does a candidate system meet them?
2. What resources are available for given candidate systems? Is the problem worth solving?
3. What is the impact of the candidate system on the organization? How well does it is fit within the
organization’s master Master Information System plan?
Each of these questions must be answered carefully. All of these questions help to investigate and to
evaluate the problem, the cost of each system and final selection of the best system.
The objective of a feasibility study is not to solve the problem but to acquire a sense of its
scope. Consequently, Cost and benefits are estimated with greater accuracy at this stage.
The result of the feasibility study is a formal proposal. This is simply a formal document detailing the
nature and scope of the proposed solution.
Analysis
Analysis is a detailed study of the various operations performed by a system and their relationships
with in and outside of the system. A key question is: -
What must be done to solve the problem?
During analysis, data are collected from the available files, decision points and transactions handled
by the current system. Tools that are used in analysis are data flow diagrams, interviews, on-site
observation, and questionnaires. The interview is a commonly used tool in analysis. Training,
experience and common sense are required for collection of the information needed to do the
analysis. Once the analysis is completed, the analyst understands that what is to be done?
Design
The tern design describes the final system and the process by which it is developed. It also refers to
the technical blue print that will be applied in implementing the candidate system. It also includes
the construction of programs and program testing. The key question is: -
How should the problem solved?
The first step in designing is to determine How the output is to be produced and in what format?
The second step is input data and master files (database) have to be designed to meet the
requirements of the proposed output.
The third step includes a list of programs needed to meet the system’s objectives and complete
documentation.
Finally, Details related to justification of the system and the impact of the candidate system on the
user and the organization. These details are documented and evaluated by management.

3. Before the implementation phase, the final reports like procedural flowcharts, records layouts, report
layouts and a workable plan are prepared for implementing the candidate system. At this point,
projected costs must be close to actual costs of implementation.
Implementation
The implementation phase is directly concerned with user training, site preparation and file
conversion. During the final testing, user acceptance testing is followed by the user training.
Conversion usually takes place at about the same time when the user is being trained. Once the
program become available and data are ready for testing and the results are OK then the program is
run with “live― data. Otherwise, a diagnostic procedure is used to locate and correct errors in
the program.
Sometime, a parallel run is conducted where the new system runs simultaneously with the
“old― system. This method may be costly but provides added assurance against errors in the
candidate system. In some cases, parallel processing is not practical possible like it is not possible to
run parallel two online point-of-sale (POS) systems for retail chain.
Post-Implementation and Maintenance
After the installation phase is completed and the user or staff is adjusted to the changes create by the
candidate system. Evaluation and Maintenance begins. If the new information is inconsistent with the
design specifications then changes have to be made. Hardware’s also require periodic
maintenance to keep in tune with design specifications.
Changes in organizations requirements or environmental factors also call for system enhancements.
This change requires evaluation, program modifications and further testing.
At last, a system project may be dropped at any time prior to Implementation. So, it is the
responsibility of the analyst to collect proper information or perform accurately every phase.