Force Kill Hanged Process During Graceful Shutdown

Hello,

We have this situation that we have a sensitive application that should not be forced-kill, so it would not corrupt some of its application data. During maintenance period like patching, we still manually stop the applications, so we can ensure the safety of our data. Manual stopping of apps are now being a burden during those kind of activities, so we are looking for ways to gracefully shutdown all the processes and applications during shutdown and reboot.
My concerns are these:
1. What if the processes are taking like 3-5 minutes to stop. Is there a graceful period when shutting down that it would force to kill a processes if it's pass that period? E.g - Unmounting of inaccessible NFS during shutdown.
2. If there are graceful period, how to configure it to increase its period?

We are aware that stopping of apps should be handled by the startup/stop scripts. We are somehow confident with our scripts, so we are just checking the other possible scenarios where our apps would be forced-kill.

Thank you everyone for checking this discussion.