Maintenance is the foundation of the entire maintenance philosophy. Unless the
PM program is effective, all subsequent maintenance activities will be
Unless the PM program is
nothing else will be.
can the success of the PM program be determined? The following indicators can
be applied to the preventive maintenance program. Each indicator has its
strength and weakness.
1. Equipment Downtime Caused by Breakdowns
first indicator highlights the impact the preventive maintenance program has on
the plant or facility. It focuses on what the PM program is designed to
eliminate: equipment breakdowns.
Downtime Caused by Breakdowns
Total Downtime expressed as a %
indicator takes the total downtime caused by the breakdown of a piece of
equipment, a department, an area, or even an entire plant or facility, and
examines it in the context of all downtime. It may be common at some plants or
facilities to refer to breakdowns as unplanned downtime. Total downtime
represents all lost time, whether due to maintenance, operations, purchasing,
transportation, or even an external supplier.
indicator identifies whether the breakdown or unplanned downtime is actually a
problem at the plant or facility. It may be that downtime is caused by another
problem, rather than the preventive maintenance program.
indicator’s largest weakness is the proper classification of downtime and the
accurate record keeping required. Downtime must be closely tracked and
categorized. If an equipment-related breakdown is not closely tracked, then the
time the operator is taking a break, procuring raw materials, or even eating
lunch may be included in the breakdown time. Such tracking inflates the
downtime and obscures other problems. Unless accurate records are kept, the
breakdown downtime becomes a “catch all” and is not useful as a management