Reverse engineering concurrent programs using formal modelling and analysis

We describe a formally based approach to reverse engineering programs with concurrent constructs. This has been a topic which has not previously been addressed, yet is required for safety critical systems and many others. To achieve this we have used a transformation based approach which has been successful in coping with sequential systems. To accommodate concurrency we have extended the core kernel language (WSL) and introduce and then prove new transformations. We then describe preliminary results. The novel aspects of this work are the application of formal program transformations to the maintenance of concurrent software, and the use of modern type theory and type checking/proof tools to extend our existing method and the tool to new domains, namely concurrency and safety critical systems.