1. Predictive Maintenance Activities
as a Percent of
Total Maintenance Activities
indicator examines the percent of maintenance activities that are predictive
compared to the other categories of maintenance work. There are two ways to
view the indicator. The first is by total hours of predictive maintenance (PDM)
time compared to all other hours of maintenance work. The second is by total
expense for the PDM program compared to the total dollars spent on maintenance.
Most of the PDM work is labor-intensive inspections. Few spare parts are used.
However, if the work tracking system can be used to highlight corrective work
resulting from predictive inspections, then the ability to compare additional
cost benefits will be available.
Hours of Predictive Maintenance
Predictive Maintenance Costs*
Total Maintenance Costs
indicators can be derived by dividing the total hours (or costs) of the
predictive maintenance activities by the total hours (or costs) worked by the
maintenance department. The resulting percentages can be trended over time to
show the level of hours or costs invested in the predictive maintenance program.
In calculating these indicators, it is best to use a weekly total and then
trend the indicator over a 12-month window.
indicator is useful for highlighting the level of predictive maintenance
activities and insuring that the PDM activities are consistent. They prevent
the predictive maintenance efforts from losing focus. If any negative trends
are noted, they can be corrected before serious problems develop with the
predictive maintenance program.
are no major weaknesses with this indicator. They should be used by any
organization serious about the predictive maintenance program.
2. Savings Attributed to Predictive
indicator highlights the savings attributed to the predictive maintenance
program. It should include equipment breakdowns that were eliminated or
prevented due to a predictive inspection. Although this may be difficult to
calculate, a real attempt should be made to quantify the savings, thereby insuring
the ongoing organizational support for the predictive program. The three major
areas of saving are:
Equipment Uptime or Downtime Avoidance Cost
Equipment Capacity or Increased Performance of the Equipment (not uptime,
but performance efficiency)
Maintenance Expense (it is less expensive to make a repair in a planned
indicators should be tracked on a monthly basis and trended over a year. They
should include an annual summary of the yearly savings since the program’s
indicators are useful for obtaining and maintaining organizational support for
the predictive effort. They can also be used as an educational tool, helping
the organization understand the impact equipment reliability has on the profits
of the company.
major weakness is the difficulty in calculating the cost avoidance. It may be
easier if cost data for a previous breakdown were accurately recorded in the
CMMS. The downtime should have been a part of the record and the loss can be
calculated from that figure. Capacity increases can compare current production
rates to the rates before the predictive program was started