Supporting Agile Reuse Through Extreme Harvesting

Agile development and software reuse are both recognized as effective ways of improving time to market and quality in software engineering. However, they have traditionally been viewed as mutually exclusive technologies which are difficult if not impossible to use together. In this paper we show that, far from being incompatible, agile development and software reuse can be made to work together and, in fact, complement each other. The key is to tightly integrate reuse into the test-driven development cycles of agile methods and to use test cases - the agile measure of semantic acceptability - to influence the component search process. In this paper we discuss the issues involved in doing this in association with Extreme Programming, the most widely known agile development method, and Extreme Harvesting, a prototype technique for the test-driven harvesting of components from the Web. When combined in the appropriate way we believe they provide a good foundation for the fledgling concept of agile reuse.