SOFTWARE QUALITY THROUGH DOMAIN-DRIVEN CERTIFICATION

Software reuse is being pursued in an attempt to improve programmer pr oductivity. The concept of reuse is to permit various work products of software development to be used on more than one project in order to amortize their development costs. Productivity is not the only advanta ge of reuse although it is the most widely publicized By incorporating reusable components into a new product, the components bring with the m whatever qualities they possess, and these can contribute to the qua lity of the new product. This suggests that reuse might be exploited f or achieving quality as an entirely separate goal from improving produ ctivity. If useful properties pertaining to quality could be shown to be present in products as a direct result of software development base d on reuse, this might be a cost-effective way of achieving those qual ities irrespective of the productivity advantages. The adjective certi fied is sometimes used to describe components that have been tested in some way prior to entry into a library but the term certified is not formally defined in the reuse literature. In this paper, we address th e issue of certifying reusable components. We advocate the development of software by reuse with the specific intent of establishing as many of the required properties in the final product as possible by depend ing upon properties present in the reusable components. For this goal to succeed, a precise definition of certification of reusable componen ts is required and such a definition is presented. The benefits of the definition and the way in which it supports the goal are explored.