When do you use a PSSR?

Most facilities I have seen only use a PSSR in conjunction with an MOC. While this is important, why are they not used every time a process gets re-started? When there is an emergency shut-down, are there important things that need to be checked before starting back up? That is what the PSSR is for! Or how about after a turnaround? Are you sure everything is lined up properly and you are ready to start the process? Use the tools you have to make sure! PSSR's are good for more than only MOCs! How do you use PSSRs at your facility?