Malik This research is on verifying the temporal correctness of synchronous digital systems. The emphasis is on obtaining accurate, efficient algorithms within the paradigm of certified timing analysis. This combines the efficiency and coverage of timing analysis with the accuracy of timing simulation. Vectors that sensitize the long paths in the combinational parts of the circuit are generated by timing analysis. These are then used in timing simulation. The research addresses the problem that in order to provide these vectors, timing analysis must consider the functionality of the circuit components.