V Shaped Model in SDLC

V Shaped Model in SDLC

V-Shaped Model

Just like the waterfall model, the V-Shaped life cycle is a sequential path of execution of processes.  Each phase must be completed before the next phase begins.  Testing is emphasized in this model more so than the waterfall model though.  The testing procedures are developed early in the life cycle before any coding is done, during each of the phases preceding implementation. Requirements begin the life cycle model just like the waterfall model.  Before development is started, a system test plan is created.  The test plan focuses on meeting the functionality specified in the requirements gathering.

•              Project and Requirements Planning – allocate resources

•              Product Requirements and Specification Analysis – complete specification of the software system

•              Architecture or High-Level Design – defines how software functions fulfill the design

•              Detailed Design – develop algorithm for each architectural component

•               Production, operation and maintenance – provide for enhancement and corrections

•              System and acceptance testing – check the entire software system in its environment

•              Integration and Testing – check that modules  interconnect correctly

•              Unit testing – check that each module as expected.

•              Coding – Transforms algorithms into software

The high-level design phase focuses on system architecture and design.  An integration test plan is created in this phase as well in order to test the pieces of the software systems ability to work together. The low-level design phase is where the actual software components are designed, and unit tests are created in this phase as well. The implementation phase is, again, where all coding takes place.  Once coding is complete, the path of execution continues up the right side of the V where the test plans developed earlier are now put to use. V-Shaped Life Cycle Model.

Advantages

• Simple and easy to use
• Each phase has specific deliverables
• Excellent choice for systems requiring high reliability – hospital patient control applications
• All requirements are known up-front
• When it can be modified to handle changing requirements beyond analysis phase
• Solution and technology are known

Disadvantages

• Very rigid, like the waterfall model.
• Little flexibility and adjusting scope is difficult and expensive
• Software is developed during the implementation phase, so no early prototypes of the software are produced.
• Model doesn’t provide a clear path for problems found during testing phases.

Sumber : http://prd4testing.blogspot.com