Page 408 - Intro Predictive Maintenance

World-Class Maintenance 399

Figure 18–3 Evalution of maintenance.

maintenance organization work (or in some cases be allowed to work) on the equip-
ment. In other words, “if it ain’t broke, don’t fix it.”

Over time, companies began to realize that when equipment breaks down it always
costs more and takes longer to fix than if it was maintained on a regularly scheduled
basis. This cost is compounded when the actual cost of downtime is calculated. Com-
panies began to question the policy, understanding that it is cost effective to allow the
equipment to be shut down for shorter periods for minor service to reduce the fre-
quency and duration of breakdowns. This leads to the second step on the road to pro-
active maintenance—establishing a good preventive maintenance program or building
on one already in place.

This step allows for the inspection and routine servicing of the equipment before it
fails and results in fewer breakdowns and equipment failures. In effect, the product is
inspected before the “customer” gets it. Some of the techniques of preventive main-
tenance include routine lubrication and inspections for major defects.

This second step, while producing some results, is not sufficient to prevent certain
types of failures. The third step, then, is to implement predictive and statistical tech-
niques for monitoring the equipment. The most common of these techniques are the
following:

• Vibration analysis
• Tribology