Testing is a vital part of software development, and it is important to start it as early as possible, and to make testing a part of the process of deciding requirements.
The testing phase of the software development lifecycle (SDLC) is where you focus on investigation and discovery. Testing does not exist in isolation, its activities are related to Software Development activities. Different development life cycle models need different approaches to testing.
There are four main stages of testing that need to be completed before a program can be cleared for use: unit testing, integration testing, system testing, and acceptance testing
whichever life cycle model is being used, there are several characteristics of good testing:
- For every development activity there is a corresponding testing activity.
- Testers should be involved in reviewing documents as soon as drafts are available in the development cycle.
- Each test level has test objectives specific to that level.
- The analysis and design of tests for a given test level should begin during the corresponding development activity.