The impact of maintainability on component-based software systems

There is a great deal of inconsistency and vagueness in the treatment of and terminology involved with software maintainability. This is exacerbated by the fact that there are a number of different dimensions of maintainability, each requiring specific treatment. The trends of increasing systems functionality and increasing systems complexity have given rise to new dimensions of maintainability since ISO/IEC defined maintainability as "the capability of the software to be modified" in 1996. We introduce the framework of maintainability and the techniques that promote maintainability in three abstraction levels; system, architecture and component. In the system dimension, the maintainability requirement is considered from a business-related point of view. In architecture, maintainability means a set of quality attributes, e.g. extensibility and flexibility. At the component level, maintainability focuses on modifiability, integrability and testability.