What is maintainability?

The definition that will be used for this blog.

I think it’s important that I give the definition that I have for maintainability, a word I will use all across this blog. The definition I base myself on is the one provided by the ISO 25010 norm. Within the ISO 25010 quality model, maintainability is one characteristic, which is divided into multiple sub-characteristics. I found the definitions of the maintainability and it’s sub-characteristics on this pdf, which sources the norm. Here they are :

Maintainability

“The degree of effectiveness and efficiency with which a product or system can be modified by the intended maintainers”, where modifications can include corrections, improvements or adaptation of the software to changes in environment, and in requirements and functional specifications. It also includes installation of updates and upgrades. It can be interpreted as either an inherent capability of the product or system to facilitate maintenance activities, or the quality in use experienced by the maintainers for the goal of maintaining the product or system [ISO 25010, §4.2.7].

Analyzability

“The 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, or to diagnose a product for deficiencies or causes of failures, or to identify parts to be modified” [ISO 25010, §4.2.7.3].

Modifiability

“The degree to which a product or system can be effectively and efficiently modified without introducing defects or degrading existing product quality” [ISO 25010, §4.2.7.4].

Testability

“The 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” [ISO 25010, §4.2.7.5].

Modularity

“The 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” [ISO 25010, §4.2.7.1].

Reusability

“The degree to which an asset can be used in more than one system, or in building other assets” [ISO 25010, §4.2.7.2].