Affordable Run-Time Verification & Validation of Fly Critical Software

The verification and validation (V&V) in distributed systems is a difficult task that is requires significant cost and effort. Our approach uses formalized attributes that are available as selectable and enforceable properties necessary for V&V of critical software. Using this information, two strategies are proposed. The first is to use executable assertions to verify at run-time that proof conditions are intact. This can be used for compositional strategies involving proof conditions. The second is more effective as system complexity increases and provides a fault tolerant middleware service that establishes properties useful for on-line V&V by software. Of particular importance is a global time property since it is very difficult to reason about timeliness for many types of proof. Furthermore, the availability of a verified timeliness property at run-time can result in significant simplification of proof conditions. The proposed Phase I effort would directly address the challenge of constructing these methods and a process for their use. WWTG will build on concepts that have been successful in the design of the x-by-wire approach for the Virginia Class submarine (VSSN).