摘要：Recovering users and systems requirements from existing information systems can be valuable in legacy systems reengineering. AMBOLS, a semiotic approach to requirements reengineering, considers recovering the requirements of an existing (legacy) system under the restriction that only the operational system and its current stakeholders are accessible, while the original system documentation may be inaccurate or unavailable. The AMBOLS approach is adopted which consists of investigative activities at three major stages with a set of techniques for analysis and representation. The techniques consider a legacy system from the perspectives of different stakeholders, from its interaction with the users in the business context, and from information content and processes of system operations. The results of analysis from these perspectives are synthesised for derivation of the requirements. A case study of a university library system is used to provide examples. Conclusions are drawn on the need and effectiveness of such an approach to reverse requirements engineering, and further work is suggested.
关键词：Requirements engineering; Legacy systems reengineering; Information systems; Organisational;semiotics; Semantics
