The percent of maintenance overtime (OT) is the total hours of maintenance work performed on overtime divided by the total hours of maintenance work performed in the same period.
Derivation: The OT computation is straightforward. In some financial systems, though, the overtime account contains only the amount of overtime premium paid. For this KPI, it’s important to do the computation in hours, since that is what we are endeavoring to control.
The amount of overtime premium is of interest, of course, but since it may vary with holidays and with the number of hours each worker has been on the job, dollars are a less precise measure of control than hours.
OT percentage is computed as follows:
Percent of maintenance work performed on overtime = total number of hours of maintenance work performed on overtime/total number of hours of maintenance work performed in the same period.
Significance: As we have said every month, the ability to plan, estimate, schedule, and complete maintenance work predictably is the foundation of maintenance cost control. Overtime is a valid tool for managing work, but uncontrolled maintenance overtime is usually the result of unplanned maintenance, and it very quickly becomes a source of uncontrolled cost. Moreover, in many work environments, when maintenance workers are called into work at unscheduled hours, they’re unable to perform their regularly scheduled duties. This may cause postponement and rescheduling of already-scheduled work with even more attendant cost and disruption of maintenance and production schedules.
In many industrial cultures, maintenance OT is a tradesman’s right. In some organizations, OT comprises most of the pay differential between production and maintenance workers. It’s also true that some maintenance work is best performed during hours that the factory is down. It still falls to maintenance management to ensure that the needs of the company and not tradesmen’s boat payments are dictating OT expenditures.
|J. Stanton McGroarty, CMfgE, CMRP, is senior technical editor of Plant Services. He was formerly consulting manager for Strategic Asset Management International (SAMI), where he focused on project management and training for manufacturing, maintenance and reliability engineering. He has more than 30 years of manufacturing and maintenance experience in the automotive, defense, consumer products and process manufacturing industries. He holds a bachelor of science degree in mechanical engineering from the Detroit Institute of Technology and a master’s degree in management from Central Michigan University. He can be reached at email@example.com or check out his Google+ profile.|
Getting started: There is no “right” OT percentage. The needs of each organization will dictate what is right for it. When OT is under management control, then other functions, such as the daily maintenance schedule, can be built around it and “self-scheduling” maintenance can be further reduced.
It should be possible to predict necessary maintenance OT and make it part of the organization’s budget. Shutdown, turnaround, and some periodic weekend maintenance, along with vacation replacements, will make up the appropriate OT load. Historic OT numbers are probably not a good starting place. This expense should be zero-based and developed with production management when the budget is initially established.
It’s also likely that the OT level for maintenance will not be uniform throughout the year. A set of monthly schedules will probably be appropriate, especially for a company that has annual or other periodic shutdowns.
Assessment of today’s situation: The cost of today’s overtime can be easily established. When assessing the impact of OT cost, make certain that the total cost, not just the cost of overtime premium, is included. Then perhaps begin with the question, “Would we be happier with some additional tradespeople or planners that this money might support than with the current OT expenditures?”
Where unscheduled OT is a factor, it is also important to identify the ripple effect that the OT has had. Have maintenance and production schedules been disrupted? Have deliveries been delayed, or is the company carrying extra finished inventory to cover system unpredictability? Does the culture accept a damaging amount of unscheduled maintenance OT?
“Yes” answers to any of these questions suggest that there is improvement and significant cost saving to be achieved from improving control of maintenance OT.