Nagios not able to detect Hang service

[lafargeuser]

I have been monitoring Remedy(Service desk tool) server & services using Nagios.
But when Remedy service hang, nagios is not able to detect problem & not sending alerts. It sends alerts when totally stop, i mean in services.msc if Remedy service is Stop/Start then alerts are sending out properly.
Frequently, we have found that Remedy(Service Desk tool) service hang & due to end user not able to login to service desk.
And since, we dont have any alerts from Nagios, it is very hard to find Root Cause of service hang.

[jsmurphy]

What you need then, is to find a way to detect the problem... are there errors in the event log? Does it create a log file with errors you can parse? Does it have an API you can query to test if it's alive?

I don't really know much about Remedy or how it works, but the program hanging is a very abstract problem. So look for available interfaces to monitor the problem and that will dictate the solution.