On the User-Requisite Variety of Computer Application Software

摘要

In this model for software maintenance, user demand for enhancements and extensions is an integral component. Such demand is directed toward obtaining the user-requisite variety of the software, which manifests itself by recognizing errors of discrimination and omission during a history of data processing. The concept of variety in data and programs is introduced and developed, and measures are suggested. Behavior of the measures over a history of data processing is investigated. Validation and application of the model is discussed.