Extracting Prime Business Rules from Large Legacy System

Business rules are operational rules that business organizations follow to perform various activities. Over time, business rules evolve and the software that implemented them is also changed. As the encompassing software becomes large and aged, the business rules embedded are substantial and difficult to extract. Furthermore, the encompassing software is changed without changing the corresponding documents, and thus often the organizations trust the code more than any other documents. It is possible to use a generic tool to extract all business rules of system however this may be an expensive exercise due to thousands upon thousands code. This paper proposes a tailored solution approach to the rule extraction problem, which consists of prime program slicing, prime domain variable identifying and data analysis, rules validation. The proposed approach has been implemented as a system and successfully experimented in a large complex financial system.