The Waterfall Model is a linear sequential software development process where each phase is completed before the next begins, and is particularly useful for projects with well-understood requirements. It was first formally described by Winston W. Royce in 1970 and has advantages like ease of implementation and early error identification, but is limited by its suitability for small projects and rigidity in handling changes. Key phases include requirement gathering, design, coding, testing, and maintenance, with documentation produced at each stage.

1. Topics
What is Waterfall Model.
History
Where to use
Diagram
Advantages
Disadvantages

2. Waterfall Model
It is also called as linear sequential model.
It was the first Process Model.
In this model whole application is developed in a
sequential approach.
It is very simple to understand and use.
In this model each phase must be completed fully
before the next phase begin.
Provides structure to inexperienced staff.

3. History
The first formal description of the waterfall
model is often cited as a 1970 article by Winston
W.Royee.
Royee presented this model as an example of a
flawed, none-working model.
It has been widely used for software projects
ever since.

4. Where to use
This SDLC model is used where requirements are
very well known.
Where definition is stable.
This SDLC model is used where the technology
are understood for the project.
And where new version of an existing product.

5. Waterfall Model Diagram
Requirements
Analysis
Design
Coding
Testing
Acceptance

6. Requirement
Gathering
In this phase business analyst will collect the
requirements with an interaction of client and
collected requirements will be documented.
Requirement
Analysis
Design
Coding
Testing
Release &
Maintenance
In this phase system analyst will study the client
requirements and prepare the system requirement
specification.
In this phase design architecture is the responsible
to decide architecture of an application in order to
full-fill the client requirements.
In this phase developers will write the program
using programming languages or scripting languages
in order to develop the application.
Initially developers will perform unit testing &
integration testing using of white box testing.
After the testing the client satisfied on work
product then we deliver application to the customer
to use at live environment..

7. Advantages
A waterfall model is easy to implement.
It helps to find errors earlier.
Easy to understand, and easy to use.
Testing is done at every stage.
Works well when quality is more important than
cost or schedule.
Documentation is produced at every stage of a
waterfall model allowing people to understand
what has been doen.

8. Disadvantages
It is only suitable for the small size projects.
Constant testing of the design is needed.
If requirements may change the waterfall model
may not work.
Adjust scope during the life cycle can kill a
project.
Difficult to estimate time and cost for each stage
of the development process.
High amount risk and uncertainty.
This is not suitable to handle dynamic changes in
the requirements.

9. Thank You!