From a "well designed" database to AD/Cycle tools: a reengineering experience

An application for the management of users and resources of a general purpose data processing center, previously developed using a manual database design methodolgy based on enriched entity relationship approach, has been redesigned using a CASE tool of the AD/Cycle "family". The existing application was based on a hierarchical DBMS (SYSTEM 2000) and was written in third generation language. The new application uses a relational DBMS (SQL/DS) and programs are written in a fourth generation language. During the reengineering phase, the conceptual schema has been slightly modified, according to new requirements and constraints; in this phase users and application programmers have been directly involved in the use of the tool. The development times, accuracy, user involvement, documentation quality, CASE tools benefits and drawbacks are discussed and compared.