Synthesizing Structured Analysis and Object-Oriented Specifications

Structured Analysis (SA) is a widely-used software development method. SA specifications are based on Data Flow Diagrams (DFD\u27s), Data Dictionaries (DD\u27s) and data transformation specifications (P-Specs). As used in practice, SA specifications are not formal. Seemingly orthogonal approaches to specifications are those using formal, object-oriented, model-based specification languages, e.g., VDM, Z, Larch/C++ and SPECS. These languages support object-oriented software development in that they are designed to specify abstract data types (ADT\u27s). We suggest formalizing SA specifications by: (i) formally specifying flow value types as ADT\u27s in DD\u27s, (ii) formally specifying P-Specs using both the assertional style of the aforementioned specification languages and ADT operations defined in DD\u27s, and (iii) adopting a formal semantics for DFD ``execution steps\u27\u27. The resulting formalized SA specifications, DFD-SPECS, are well-suited to the specification of distributed or concurrent systems. We provide an example DFD-SPEC for a client-server system with a replicated server. When synthesized with our recent results in the direct execution of formal, model-based specifications, DFD-SPECS will also support the direct execution of specifications of concurrent or distributed systems