Waterfall Model

• Waterfall Model is introduced by Winston Royce in 1970.
• Waterfall model is also known as
         1.classic life cycle
         2.linear sequential model
• It describes a systematic, sequential approach to software development which starts at the system level and progresses through analysis, design, coding, testing, and support.

• Traditional waterfall model is a one-way linear sequence.

• The Waterfall Model includes the following activities:

1. Plan and Analyse/Software requirements analysis: This process is done at strategic business level and at business area level. The requirement document mainly consists of “what the system should do?”.

2. Design: Data structure, algorithmic details and software framework and architecture are the key parameters involved in software design. The design process translates requirements into a representation of the software.

3. Build/Code Generation: In Build phase, all the design documents are translated into code which are written in programming languages.

4. Test: In test phase, Testers play a vital role in detecting the bugs in the developed software product, not to debug bugs.It also done to verify whether the product is meeting the functional requirements.

5. Deploy:After Development and Testing, product is deployed in Go-Live environment.

• Advantages of Waterfall Model:

1. It is easy to use.
2. It guides in making structured,disciplined and stable software product.
3. It includes planned and properly defined milestones and baselines

• Disadvantages of Waterfall Model:

1. Requirements must be completely gathered at the inital stage itself.
2. Each stage of the development is frozen before proceeding to the next stage.
3. Not much interactio between client and developer.

What is SDLC?

• SDLC stands for Software Development Lifecycle.
• It is defined as the sequential steps of process taken to produce a software product.

• Software development process is divided into different stages.

Plan/Analyze->Gathering Requirements.
Design->Completing Project Specification
Develop->Completing Product Development
Test->Completing testing of the product
Release/Deploy->Go-live

• SDLC plays a key role in describing the activities taking place in each stage of software development.

• SDLC kick starts right from the capability of the product is conceived to the production.

• In other words,SDLC is initiated from requirements phase to deployment phase.
• SDLC implies the associations and relationships between project phases.The project phases are including exit and entry criteria,reviews,feedback mechanisms,walkthroughs,milestones,deliverables and baselines

Uses of SDLC:

• Guide to testers,project managers,business analysts,developers and other people involved in software development.
• It avoids discrepancies in software development.

• It minimizes the old code-and-fix-process.

Common SDLC Models:

• Water fall model
• Incremental/Overlapping Model
• Prototyping Model
• Spiral Model