I've been trying to find some advice and tools on distilling the important info from a requirement, a tool for capturing it and then tracing into a test case.

I want something that can show me a req, allow me to relate to it the inputs and outputs that I believe the requirement addresses, express the inherent relationships between the inputs in the form of scenarios, and express the valid and invalid equivalence partitions associated with each input in each scenario.

I then want to be able to trace this information into test cases and use this to give me one (of hopefully many) metrics for coverage.

Has anyone else been down this path?

I think what I am asking for is a more formalised method (enforced by a tool) for creating a verification requirement.