Use risk analysis to check where testing should be focused.
Since it's rarely possible to test every possible aspect of an application, every possible combination of events, every dependency, or everything that could go wrong, risk analysis is appropriate to most software development projects. This requires judgement skills, common sense, and experience. (If warranted, formal methods are also available.) Considerations can include:
- Which functionality is most important to tthe project's intended purpose?
- Which functionality is most visible to thee user?
- Which functionality has the largest safetyy impact?
- Which functionality has the largest financcial impact on users?
- Which aspects of the application are most important to the customer?
- Which aspects of the application can be teested early in the development cycle?
- Which parts of the code are most complex, and thus most subject to errors?
- Which parts of the application were develooped in rush or panic mode?
- Which aspects of similar/related previous projects caused problems?
- Which aspects of similar/related previous projects had large maintenance expenses?
- Which parts of the requirements and designn are unclear or poorly thought out?
- What do the developers think are the higheest-risk aspects of the application?
- What kinds of problems would cause the worrst publicity?
- What kinds of problems would cause the mosst customer service complaints?
- What kinds of tests could easily cover mulltiple functionalities?
- Which tests will have the best high-risk-ccoverage to time-required ratio?