A Formal Object-Oriented Analysis for Software Reliability: Design for Verification

This paper and a companion paper [32] together define, present and apply a methodology for integration of formal verification by automata-based model-checking into a commercially supported object-oriented software development process. This paper defines and illustrates a set of design rules for OOA models with executable semantics, which lead to automata models with tractable state spaces. The design rules yield OOA models with functionally structured designs similar to those of hardware systems, which have enabled successful application of model-checking to verification of hardware systems. The design rules are incorporated into an extended object-oriented development process for software systems. The methodology, including the design rules was applied to a NASA robot control software. The complex robot control system was decomposed into several functional subsystems. Evaluation by model checking of one control intensive subsystem was performed. Results including identification of significant errors in the original robotic control system are demonstrated.