Page 82 - Intro Predictive Maintenance

Benefits of Predictive Maintenance 73

behavior before the system is restarted. This ability eliminates the need for the second
outage that is often required to correct improper or incomplete repairs.

Data acquired as part of a predictive maintenance program can be used to schedule
and plan plant outages. Many industries attempt to correct major problems or sched-
ule preventive maintenance rebuilds during annual maintenance outages. Predictive
data can provide the information required to plan the specific repairs and other
activities during the outage. One example of this benefit is a maintenance outage
scheduled to rebuild a ball mill in an aluminum foundry. The normal outage,
before predictive maintenance techniques were implemented in the plant, to com-
pletely rebuild the ball mill was three weeks, and the repair cost averaged $300,000.

The addition of predictive maintenance techniques as an outage-scheduling tool
reduced the outage to five days and resulted in a total savings of $200,000. The
predictive maintenance data eliminated the need for many of the repairs that would
normally have been included in the maintenance outage. Based on the ball mill’s
actual condition, these repairs were not needed. The additional ability to schedule
the required repairs, gather required tools, and plan the work reduced the time required
from three weeks to five days.

The overall benefits of predictive maintenance management have proven to substan-
tially improve the overall operation of both manufacturing and processing plants. In
all surveyed cases, the benefits derived from using condition-based management have
offset the capital equipment costs required to implement the program within the first
three months. Use of microprocessor-based predictive maintenance techniques has
further reduced the annual operating cost of predictive maintenance methods so that
any plant can achieve cost-effective implementation of this type of maintenance man-
agement program.