V-Shaped SDLC Model Lecture-6

6.1 V-Shaped SDLC Model The Verification and Validation Model commonly known as V – Shaped Model An extension of the Waterfall Model that emphasizes the verification and validation of the product. Like Waterfall model different phases progress in a sequential manner. Testing of the product is planned in parallel with a corresponding phase of development

6.2 V-Shaped SDLC Model

6.3 V-Shaped Steps System Requirements Analysis – allocate resources and provides complete specification of the software system Software Architecture or High-Level Design – defines how software functions fulfill the design Detailed Design – develop algorithms for each architectural component Coding – transform algorithms into software

6.3 V-Shaped Steps Contd 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. Unit testing – check that each module acts as expected Integration and Testing – check that modules interconnect correctly. System and acceptance testing – check the entire software system in its environment

6.4 V-Shaped Strengths Emphasize planning for verification and validation of the product in early stages of product development Each deliverable must be testable Easy to use and saves time since the testing team is involved at the beginning. Works well for small projects where requirements are easily understood.

6.5 V-Shaped Weaknesses Does not easily handle concurrent events Does not handle iterations or phases Does not easily handle dynamic changes in requirements Does not contain risk analysis activities Very rigid and least flexible like waterfall model. If any changes are required the SRS document and test documents etc to be updated.

6.6 When to use the V-Shaped Model 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

6.7 Comparison of Different Life Cycle Models Iterative waterfall model most widely used model. But, suitable only for well-understood problems. Prototype model is suitable for projects not well understood: user requirements technical aspects

6.7 Comparison of Different Life Cycle Models (CONT.) Evolutionary model is suitable for large problems: can be decomposed into a set of modules that can be incrementally implemented, incremental delivery of the system is acceptable to the customer. The spiral model: suitable for development of technically challenging software products that are subject to several kinds of risks.

6.8 The choice for Software Lifecycle Model The selection for a software lifecycle model for a project is an important decision. The choice of the life cycle model is based on the following factors: Overall cost of the software lifecycle used. Software development speed Software quality The ability to tracking and control the project The project’s overhead The level of risk associated with the project Client relations