Software life cycle models describe phases of the software cycle and the order in which those
phases are executed. Each phase produces deliverables required by the next phase in the life
cycle. Requirements are translated into design. Code is produced according to the design
which is called development phase. After coding and development the testing verifies the
deliverable of the implementation phase against requirements. The testing team follows
Software Testing Life Cycle (STLC) which is similar to the development cycle followed by
the development team.
There are following six phases in every Software development life cycle model:
Requirement gathering and analysis
Design
Implementation or coding
Testing
Deployment
Maintenance
1) Requirement gathering and analysis: Business requirements are gathered in this phase.
This phase is the main focus of the project managers and stake holders. Meetings with
managers, stake holders and users are held in order to determine the requirements like; Who
is going to use the system? How will they use the system? What data should be input into the
system? What data should be output by the system? These are general questions that get
answered during a requirements gathering phase. After requirement gathering these
requirements are analyzed for their validity and the possibility of incorporating the
requirements in the system to be development is also studied.
Finally, a Requirement Specification document is created which serves the purpose of
guideline for the next phase of the model. The testing team follows the Software Testing Life
Cycle and starts the Test Planning phase after the requirements analysis is completed.
2) Design: In this phase the system and software design is prepared from the requirement
specifications which were studied in the first phase. System Design helps in specifying
hardware and system requirements and also helps in defining overall system architecture. The
system design specifications serve as input for the next phase of the model.
In this phase the testers comes up with the Test strategy, where they mention what to test,
how to test.
3) Implementation / Coding: On receiving system design documents, the work is divided in
modules/units and actual coding is started. Since, in this phase the code is produced so it is
the main focus for the developer. This is the longest phase of the software development life
cycle.
