What is waterfall model ?

waterfall model::

The classic life cycle model or the waterfall model suggests a systematic, sequential approach to software development that begins at the system level and progress through analysis, design, coding, testing, and support.

Software Requirements Analysis:

The requirements gathering process is increased and focused only on software. To understand the nature of the software to be built, the software engineer ("analyst") must understand the information domainof the software as well as required function, behavior, performance, and interface. Requirements for both the system and the software are documented and reviewed with the customer.

Design:

Software design is a stepwise procedure that focuses on four distinct properties of a program: data structure, software design, interface illustration, and procedure (algorithmic) details. The design process transforms into a representation of the software that is evaluated for quality before coding begins. Like requirements, the design is also documented and becomes part of the software configuration.

Code Generation:

 The code generation step translates the design into a machine readable form. If design is performed in a detailed manner, code generation can be accomplished automatically.

Testing:

 Once code has been generated, programl testing starts. The testing process ensure that all statements have been tested, and the functional external; that is, conducting tests to uncover errors and ensure that defined input will produce actual results that agree with expected results.

Supports:

  Software will certainly undergo change once it is delivered to the customer. change will occure because errors occure, and because the software must be adapted to accommodate changes in the extarnal environment (e.g. due to new operating system or peripheral device), or because the customer requires some functional or performance enhancements. Software support/maintenance reapplies each of the preceding phases to an existing program rather than a new one.