Exercise 6: CBM with periodic monitoring Let us consider a condition-based maintenance policy whereby the degradation () is monitored at periodic inspections, carried out at times . After each inspection, one of the following three actions takes place: If () < , do nothing until next inspection time If () < , perform PM (at cost ) If () , perform CM (at cost ) We further assume that replacement time is negligible. Derive a formula for the ECL and ECC