10 key indicators of maintenance performance

By Edwin K. Jones -- Plant Engineering, 1/1/1999

The "business contribution" of maintaining personnel is to provide highly reliable equipment at the lowest possible cost. World-class plants are typically driving reliability rather than cost reduction. (Industry sensitive)

- Ratio of direct maintenance personnel to support maintenance personnel

World-class plants tend to fall in the range of 2:1 to 3:1 workers per support person. Support personnel are those who provide the supervision, parts management, planning, reliability improvement, equipment condition monitoring, and other supporting tasks for the "hands on" workers.

- Ratio of direct maintenance personnel to maintenance planning personnel

- Ratio of direct maintenance personnel to engineering and technical maintenance personnel

There is usually a correlation between this metric and a plant's equipment reliability and costs.

- Maintenance cost as a percentage of plant estimated replacement value

This value is a classic measure of maintenance cost. Unfortunately, by itself, it drives cost reduction behavior without necessarily reinforcing the need for improved maintenance practices.

- Ratio of plant estimated replacement value (in millions) to direct maintenance workers

This value is a measure of direct maintenance worker productivity ("How much plant and equipment,

in dollars, can each worker maintain?"). Many world-class plants fall into the range of $6-$9 million/worker. (Somewhat industry sensitive)

- Maintenance contracting cost as a percentage of total maintenance cost

This value is a measure for comparison, but without a "target" value. World-class plants don't shoot for a specific level; rather, they are disciplined in defining the role of contractors in maintenance, based

on business-related criteria. On average, top plants around the world contract over 30% of their maintenance work -- a little less in the United States. But, top plants are driven by a defined

strategy, not a target percentage.

- Stores parts and investment as a percentage of plant estimated replacement value

For years, the target for this measure was about 1%, but top plants around the world now routinely achieve ratios in the range of 0.25%-0.5%

- Stores turnover (ratio of annual disbursements to inventory value)

This ratio reflects stocking strategy and may run above or below 1 depending on the plant's strategy (for example, balancing risk against insurance stocks). Performance is measured against the plant's own target.

- Ratio of stores disbursements to stores personnel (dollar investment/stores person)

This value is a measure of "productivity" of the stores operation and associated personnel.