How to do post-synthesis simulation in ModelSim?

Hi Dave, I suddenly find you mentioned this: "the test sequences test each operating mode of the device, and the TimeQuest indicates the design meets timing, then you can just test the design in hardware. "

So how can I know whether design meets timing? Through timing analysis? Sometimes after I finish completed compilation, there is critical warning that indicates the design does not meet timing requirements, but I don't know how to handle it.

Thanks.