Preventive Maintenance

Preventive Maintenance is the foundation of the entire maintenance philosophy. Unless the PM program is effective, all subsequent maintenance activities will be sub-optimized.

In short:

Unless the PM program is successful,

nothing else will be.

How 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

The 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 %

This 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.

Strengths

This 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.

Weaknesses

This 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 tool.