Test Life Cycle / Software Testing models

This page contains a brief description on the Life Cycle and the different Testing Models.

SDLC:

The software development life cycle (SDLC) is a conceptual model used in project management that describes the stages involved in an information system development project, from an initial feasibility study through maintenance of the completed application/product.


Phases of SDLC

  • System Study
  • Feasibility Study
  • Requirements
  • Design
  • Coding
  • Testing
  • Implementation
  • Maintenance

    V-Model:

    The V-Model shows and translates the relationships between each phase of the development life cycle and its associated phase of testing. The V-model is a software development model which is considered to be an extension of the waterfall model. Instead of moving down in a linear way, the process steps are targeted upwards after the coding phase, to form the typical V shape.

    Requirements analysis: In this phase, the requirements of the proposed system are collected by analyzing the needs of the user(s). This phase is concerned about establishing what the ideal system has to perform. However, it does not determine how the software will be designed or built. Usually, the users are interviewed and a document called the user requirements document is generated. The user requirements document will typically describe the system’s functional, physical, interface, performance, data, security requirements etc as expected by the user. The user acceptance tests are designed in this phase.

    System Design: System engineers analyze and understand the business of the proposed system by studying the user requirements document. They figure out possibilities and techniques by which the user requirements can be implemented. If any of the requirements are not feasible, the user is informed of the issue. A resolution is found and the user requirement document is edited accordingly.

    The software specification document which serves as a blueprint for the development phase is generated. This document contains the general system organization, menu structures, data structures etc. It may also hold example business scenarios, sample windows, reports for the better understanding. Other technical documentation like entity diagrams, data dictionary will also be produced in this phase. The documents for system testing is prepared in this phase.

    High-level design: This phase can also be called as high-level design. The baseline in selecting the architecture is that it should realize all which typically consists of the list of modules, brief functionality of each module, their interface relationships, dependencies, database tables, architecture diagrams, technology details etc. The integration testing design is carried out in this phase.

    Low-level design: This phase can also be called as low-level design. The designed system is broken up in to smaller units or modules and each of them is explained so that the programmer can start coding directly. The low level design document or program specifications will contain a detailed functional logic of the module, in pseudo-code - database tables, with all elements, including their type and size - all interface details with complete API references- all dependency issues- error message listings- complete input and outputs for a module. The unit test design is developed in this stage."

    VModel

    References: wikipedia.