Testing throughout the software life cycle

Testing is not a stand-alone activity. It has its place within a software development life cycle model and therefore the life cycle applied will largely determine how testing is organized.

There are many different forms of testing. Because several disciplines, often with different interests, are involved in the development life cycle, it is important to clearly understand and define the various test levels and types.

Software Development Models

The development process adopted for a project will depend on the project aims and goals. There are numerous development life cycles that have been developed in order to achieve different required objectives. 

These life cycles range from lightweight and fast methodologies, where time to market is of the essence, through to fully controlled and documented methodologies where quality and reliability are key drivers.

It will define the what, where, and when of our planned testing, influence regression testing, and largely determine which test techniques to use. The way testing is organized must fit the development life cycle or it will fail to deliver its benefit.

In every development life cycle, a part of testing is focused on verification testing and a part is focused on validation testing. 

Verification is concerned with evaluating a work product, component or system to determine whether it meets the requirements set. In fact, verification focuses on the question 'Is the deliverable built according to the specification?'. 

Validation is concerned with evaluating a work product, component or system to determine whether it meets the user needs and requirements. Validation focuses on the question 'Is the deliverable fit for purpose, e.g. does it provide a solution to the problem?'