PM Schedule - Last Update History

Hi All,

I got an interesting question from my client on Preventive Maintenance schedule - Last Update History. When an field in Activity Association table eg - source code is updated today and save it. My Preventive Maintenance schedule shows last updated history as today. I know there is interdependency between these tables so when you update the activity association, it triggers the update in PM schedule table. Why the PM Schedule table is getting updated when i update Activity Association Table?

This question has come since there was some discrepancy in User access and use of the Auditing in the system.