Preventive Maintenance KPIs

Hidear all,

I trust you are all well !
I request your help regarding the optimization of preventive maintenance on heavy equipment (dumper, dozer, loader etc).
I would to have a list of metrics or KPIs , ( like the schedule compliance for instance) to “measure” the preventive maintenance. It would be very helpful If I can know on which basis to calculate those metrics and how to do it (daily , weekly, monthly, on a group of machines?). Any help would be appreciated.

Thanks in advance

Preventive Maintenance KPIs