Road to riches
Richard L. Dunn, Editor -- Plant Engineering, 6/1/2002
A survey on predictive maintenance (PdM) discussed in the Plant Engineer's Handbook (2001, Butterworth-Heinemann, Woburn, MA. ISBN 0 7506 7328 1) makes PdM sound like a pot of gold. The survey included 500 plants in a wide variety of industries.
Here are some of the benefits reported:
- Reduction by an average of 55% in the number of catastrophic machine failures
- Average reduction of 60% in mean time to repair (MTTR)
- More than 30% reduction in spare parts inventories
- Average increase of 30% in the useful operating life of plant equipment
- Availability of process systems increased by 30%
- Consistent reductions in mean time between failure (MTBF)
- Reduced potential for destructive failure with a commensurate reduction in potential for injury or death
- Verification of new equipment condition and installed condition at acceptance
- Verification of rebuilds and repairs
- Improved planning and scheduling
- Elimination of unnecessary repairs.
"In all surveyed cases," the book reports, "the benefits derived from using condition-based management [PdM] have offset the capital equipment cost required to implement the program within the first three months."
That's a pretty impressive list of benefits.
So, why isn't PdM an active program in every plant? There are many reasons, of course. But chief among them has to be that many plants are not yet up to speed in preventive maintenance (PM), the system that provides the foundation for any PdM program.
Predictive maintenance is not a hit-or-miss proposition. The monitoring at the heart of the program is time based. That means it requires rigorous scheduling and schedule compliance. And that means PM must be in place first.
A frequent roadblock to good PM programs is the lack of priority given them by operations and production managers who just aren't all that convinced that PM schedule compliance is important. If you're having that kind of problem, you might want to dangle the PdM carrot in front of them.
The road to PdM and its potential pot of gold at the end runs through PM.
