This characteristic represents the degree of effectiveness and efficiency with which a product or system can be modified to improve it, correct it or adapt it to changes in environment, and in requirements. This characteristic is composed of the following sub-characteristics:
- Modularity - Degree to which a system or computer program is composed of discrete components such that a change to one component has minimal impact on other components.
- Reusability - Degree to which a product can be used as an asset in more than one system, or in building other assets.
- Analysability - Degree of effectiveness and efficiency with which it is possible to assess the impact on a product or system of an intended change to one or more of its parts, to diagnose a product for deficiencies or causes of failures, or to identify parts to be modified.
- Modifiability - Degree to which a product or system can be effectively and efficiently modified without introducing defects or degrading existing product quality.
- Testability - Degree of effectiveness and efficiency with which test criteria can be established for a system, product or component and tests can be performed to determine whether those criteria have been met.