Formal sign-off is possible with today’s technology and methodology. But to get to formal sign-off takes an understanding of what is possible with formal verification, and an immersion in ongoing practice with formal methods and techniques. Moreover, early experiences with formal can determine later success with formal verification and sign-off. Even with a deep knowledge of a formal verification tool and extensive training from the tool vendor, exponential formal proof complexity often gets in the way of exhaustive coverage. Often what is needed is training in formal verification methodology and formal test planning that includes an exhaustive list of end-to-end checkers, as well as the mastering of formal techniques that help overcome complexity. (more…)