Complementing semi-formal specifications with Z

The insertion of formal techniques into the daily practice of software engineering definitely improves the quality of specifications. An approach is proposed where semi-formal specifications are translated into the formal specification language Z and enriched by formal annotations. The paper starts from a specification of an access control system using classical description techniques: entity-relationship schemas, data-flow diagrams, and state machine descriptions. It shows how these can be combined with formal definitions of types, constraints and functions.