Hi, This may seem a bit simple but I’m having trouble with a manager who is approving a retrospective validation (OQ) protocol. I have a list of alarms that I can stimulate, which is fine, and then more alarms that I cannot stimulate due to catastrophic damage/failure to the equipment. These alarms are listed and an explanation beside each stating why they cannot be tested (e.g. would need to damage the motherboard!!!), but now the approver wants to know how I know that these untested alarms work! Normally there would be some sort of manufacturers documentation to reference, but this piece of equipment is here over 20 yrs, so no paperwork!!! I have searched FDA guidelines high and low to find an actual statement stating that if catastrophic failure occurs do not need to test alarms but so far cannot come up with anything! Fact is, I don’t know if alarms work unless machine decides to pack itself in or we cut interlocksE-Stops/ etc, but this doesn’t seem to cut it with him!Any ideas???
Get him to foot the bill for the destructive testing! 
Given the age of the system, I’m guessing you don’t have the source code? If you did, you could maybe do a code inspection or some kind of unit testing for these cases.
Other than that, maybe you can do a risk assessment? Appeal to his “validation should be risk-based” side and show that (presumably) in such a state of degradation, product wouldn’t be produced or would be immediately recognizable?
Maybe have a team meeting and discuss the options and issues. Get inputs from him, Quality, engineering, and operations. Maybe the team can come up with a plan.
Tough one.
Create a spread sheet and list your top 10 alarm tests that would be the most costly to repair should the test be simulated and an actual fault created. List the cost to repair after each test to allow you to continue to the next one. List the approximate production down time for each repair. Take that information to the Validation Committee and request that they resolve the issue so that you may continue with your other projects.Request that they complete a Risk assessment to ensure that the testing would be 'BAD" for the company financialy and that it poses no risk to Product or patient.
In reality we all seem to get the one ‘crazy’ fool that is a stick in the spokes but common sense will prevail when there are more than 2 educated disciplines that have to make the call on that type of testing.
Hope this is of some help in the future.