Software Architect's Handbook

Categories of fitness functions

There are different categories of fitness function. They are not mutually exclusive. For example, a fitness function could be both atomic and temporal. The different fitness function categories include:

Atomic versus holistic

Atomic fitness functions focus on a single context and on one architectural characteristic. For example, a unit test that is designed to test one architectural characteristic is atomic. A holistic fitness function takes multiple architectural characteristics into consideration at the same time.

Having both atomic and holistic fitness functions is useful because a feature that works fine when tested atomically could fail when it is combined with other features. It isn't feasible to test ...