Verification and Validation of Flight Critical Systems

Verification and Validation is a multi-disciplinary activity that encompasses elements of systems engineering, safety, software engineering and test. The elements that go into the V&V of a complex, software intensive product come out of activities that are performed by all of these disciplines while also spanning the complete system development cycle. As modern systems become more reliant on software intensive solutions to perform mission and safety critical functions, the effort that is required for system certification experiences a corresponding increase. These systems are expected to perform correctly and safely while being flexible and portable enough to go though system refresh cycles and evolvable enough to take on new system functionality throughout the system lifecycle. . We propose a method of addressing this challenge with advanced modular safety cases to specify system safety properties and support the V&V of those properties with argument and evidence chains. The modular safety cases make use of formal specification of safety claims and use contracts to formalize the dependencies between the case modules. These cases can be used to form powerful verification and validation arguments for a system that are maintainable and can be used to support incremental V&V techniques.