System development life cycle(SDLC) and Comparison of Waterfall, Spiral, prototype and Iterative model

System development life cycle(SDLC) and Comparison of Waterfall, Spiral, prototype and Iterative model

System development life cycle is a process which is used in an information system, software engineering, and system engineering.

System development life cycle consists of six main phases to build a hardware system, or software system or combination of both to meet user expectation.

comparison of SDLC software models
Figure: SDLC 

Why we used system development life cycle  

System development life cycle provides a guideline or serves as a conceptual model in software development project.

SDLC stages contain complete guideline from an “initial feasibility study through maintenance of the completed application.

We used this guideline to accomplish our project effectively and efficiently.

Comparative Analysis of software engineering Models

System development life cycle is a structured plan for developing software project.

It is the methodology of the framework used to develop the plan, analysis, design, implementation, and maintenance. Choosing a best (SDLC) method for your project is an essential to the success of your project.

In this comparative analysis, we discuss benefits and problem in different (SDLC) methodology,

Likewise waterfall, spiral, prototype, and iterative models.

Features Iterative model Spiral model Waterfall model Prototype model
Requirement specification Well understood Well understood Not well understood Not well understood
Cost estimation Less costly High cost Difficult to estimate cost High cost
Risk Analysis Less risk Very high Risk not cover Minimum risk
Software compatibility For big project For big project For big project Complex
Complexity Less complex Complex Complex Flexible
Flexibility Flexible Flexible Poor flexible Suitable for small project
User involvement User involvement exist User involvement exist No user involvement High user involvement
Success-Rate  High success rate High success rate No high success rate High success rate



It is the essential phase of IT/Software development industry, a project and its level of success are only as good as its planning.

In this phase desired feature and operation discuss in detail, including screen layout, business rules, process diagram, and other documentation.

Feasibility criteria of proposed system were also checked in this phase.

All the necessary borrowed form customer at this stage.   

System Analysis:

The objective of this phase is to conduct analysis like finding the problem in the

company and propose solutions, after this evaluate the solution on the bases of cost and other sources which will be used to accomplish the task and submit a suitable solution.

Tools which are used in this phase include requirements gathering structure analysis and (CAS) A computer-aided system software engineering.

Systems Design:

In this phase, engineer constructs paperwork or diagram on the bases of information which collected from the customer in previous stages like planning stage and analysis phase. System design is the third stage of (SDLC) system design contains two main area, logical system design, and physical system design, logical system design looks like a (blueprint) of the system and physical which shows in detail cost and materials of a system. The diagram contains all the essential aspect which provides the guideline for the consultant when they develop your project.


Now the project is ready for implementation, in implementation phase real code is written the actual working environment (training is most important in this phase). A direct cutover usually takes place during off-peak hours but it could be risky and difficult. The old data is moved into new system and installation of the system component.


In this phase, we made changes, correction, additions, and moves.This, the least and perhaps most important phase of all, may go on forever.