1.2.1 Testing’s Contributions to Success

Throughout the history of computing, it is quite common for software and systems to be delivered into operation and, due to the presence of defects, to subsequently cause failures or otherwise not meet the stakeholders’ needs. However, using appropriate test techniques can reduce the frequency of such problematic deliveries, when those techniques are applied with the appropriate level of test expertise, in the appropriate test levels, and at the appropriate points in the software development lifecycle. Examples include:

• Having testers involved in requirements reviews or user story refinement could detect defects in these work products. The identification and removal of requirements defects reduces the risk of incorrect or untestable features being developed.

• Having testers work closely with system designers while the system is being designed can increase each party’s understanding of the design and how to test it. This increased understanding can reduce the risk of fundamental design defects and enable tests to be identified at an early stage.

• Having testers work closely with developers while the code is under development can increase each party’s understanding of the code and how to test it. This increased understanding can reduce the risk of defects within the code and the tests.

• Having testers verify and validate the software prior to release can detect failures that might otherwise have been missed, and support the process of removing the defects that caused the failures (i.e., debugging). This increases the likelihood that the software meets stakeholder needs and satisfies requirements.

In addition to these examples, the achievement of defined test objectives (see section 1.1.1) contributes to overall software development and maintenance success.