Waterfall Model

The waterfall model consists of 5 phases:

1. Requirements (in which the customer requirements are written).
2. Design (in which the high and low-level design documents are written).
3. Code (in which the code is written and (hopefully) unit tested).
4. System test (which is where we come in).
5. Installation and cut over.


Disadvantages of waterfall model

1. Bureaucrats believe such phases are finite and cannot be iterated upon.
2. It doesn’t allow for parallel activities such as prototyping or the development of user interface.
3. specifications or for safety-critical system issues such as the development of a safety case.
4. It makes no mention of contract preparation, project management, reviews, or audits.
5. It implies that system testing starts only when coding is finished.
6. It says nothing about software reuse.

Advantages of waterfall model

1. Each phase generates some baseline deliverable.
2. It is well-known.
3. It has been used for many years.
4. It is very adaptable.
5. Each process can be decomposed into others.
6. You can add any process you want.

Here

1. Each phase may have to be repeated (as requirements change, as prototypes evolve).
2. It needs to be seen in parallel with a number of other life-cycles with which it must stay synchronized.
3. It can be modified for prototypes and software reuse.
4. Testing input begins at least as early as requirements definition .
5. Any change to requirements, design, or code must be manually reflected through all levels of documentation to ensure all documents are consistent . then it is perfectly usable.

Related :

Managing risk in software testing
SOFTWARE QUALITY ASSURANCE AND CONTROL

SOFTWARE QUALITY AND COST ASPECT

STABLE PROCESS OF SOFTWARE TESTING

STABLE PROCESS OF SOFTWARE TESTING PART TWO

DEFECTS IN SOFTWARE TESTING

REDUCTION OF DEFECTS IN SOFTWARE TESTING

SOFTWARE TESTING AND EFFECTING FACTORS

SCOPE OF SOFTWARE TESTING

TESTING LIFE CYCLE PART ONE

TESTING LIFE CYCLE PART TWO

TESTING LIFE CYCLE PART THREE

SOFTWARE TESTING AND CONSTRAINTS WITH IN IT