Research Heaven West Virginia A Compositional Approach for

Research Heaven, West Virginia A Compositional Approach for Validation of Formal Models Bojan Cukic, Dejan Desovski West Virginia University NASA OSMA SAS '04

Approach Research Heaven, West Virginia • Using test coverage measures, decompose the formal specification model. – Abstract the thoroughly tested parts, use model checking on the rest of the specification. • Demonstrate that visual interfaces hide the complexity of the specification model. – Develop methodology for creation of visual interfaces. – Use them for representing the coverage metrics too. • Extend the SCR toolset – Monitoring specification test coverage. – Automatic decomposition of the specification. – Compositional verification. 3

Importance/benefits Research Heaven, West Virginia § Verification and validation of formal models suffers from significant practical drawbacks. § Practical and automated assurance of specifications is an open research problem. § Integration of model testing and visual specification interfaces. § § Facilitates variable and interaction abstraction. Abstractions reducing the state-space of the models. § A compositional framework for verification and validation of system specification models. § Exploit the ease of testing, and the completeness of the model checking. § Extending a mature toolset (SCR). 4

Relevance to NASA Research Heaven, West Virginia • Incomplete, inconsistent, unstable system requirements a major mission assurance problem. – Brian O’Connor’s address at NASA IV&V, June 04. • Proposed approach to be evaluated on NASA case studies. – Fault Protection Engine (FPE) System at JPL. – Other case studies wanted/needed. • Ongoing case studies on formal specification. 5

Accomplishments Research Heaven, West Virginia • Test coverage of SCR specification constructs study completed. – Formally defined coverage criteria applicable to SCR specifications. – SCR’s simulator utilized for automated coverage tracking. – Coverage tracking tool developed, applied to Safety Injection System. 6

Next Steps Research Heaven, West Virginia § Continue the research on SCR specification test coverage, visualization, abstraction, additional case studies. § Develop a methodology for building visual interfaces of generic SCR specifications. § Investigate visual interfaces suitable for specification verification and validation. § Integrate visualization toolset with the coverage tracking tool. § Research on automated specification abstraction from test coverage metrics. 7