Are you doing the right work at the right time?
Stanton McGroarty says reactive maintenance destroys OEE, creating a huge competitive disadvantage.
By J. Stanton McGroarty, CMfgE, CMRP, senior technical editor
The “percent of work completed on time” KPI is the percentage of the work completed during a time period that was done on schedule. The percentage can also be computed for types of work, either by trade or by urgency category, or by origin, such as PM or PdM work.
Derivation: To be completed on time, work must first be completed. Work that is begun but not completed is excluded from the computation until next period. Work is not truly completed until the costs and lessons learned have been captured for future decision making. This is the organization’s best defense against solving the same problems time after time. A maintenance work order has been completed when production can return to normal operations and maintenance has consigned the job to the record books and made ready to begin the next work order.
To maintain this KPI it is necessary to establish a method for setting expected completion dates. Some maintenance scheduling systems have start and finish date fields for work orders. Some have only start dates and estimated durations. It may be necessary for the organization to agree on what it will use for work order due dates. Consistency is more important here than the precise definition, but a clear definition of completion is essential.
As with most percentage-of-work KPIs, percentage completion can be computed in two ways:
Percent of Work Completed on Time = Total Number of Maintenance Work Orders Completed on Time/Total Number of Maintenance Work Orders Completed in the Same Period
Percent of Work Completed on Time = Total Man Hours of Maintenance Work Completed on Time/Total Man Hours of Maintenance Work Completed in the Same Period
Tracking the percentage of work orders completed is recommended, as the two measures tend to track closely. There may be a tendency at first to reduce the scope of work orders to provide earlier closure and a higher score. This is to be avoided, since it tends to leave work undone.
|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 firstname.lastname@example.org or check out his Google+ profile.
Significance: The ability to plan, estimate, schedule, and complete work predictably is the foundation of controlled maintenance operations. If this basic sequence of operations cannot be established or is constantly interrupted, all asset health care performance is in jeopardy.
On-time-completion rates of less than 80% indicate that a maintenance area is out of control. Sadly, measurement and improvement often starts with effective rates of 0%, since definitions of completion are often not in place to support scorekeeping.
Here are the dominos. Control of maintenance cost is impossible until the maintenance organization can plan work before committing resources. Without planning, it is impossible to estimate what resources will be tied up on a job and for how long. Without resource availability data, schedules are meaningless. Without valid schedules, equipment availability will be unknowable. Without predictable equipment availability, overall equipment effectiveness (OEE) becomes meaningless. Thus, when maintenance is out of control, so is production.
The journey from 80% to 90% on the completion KPI is when predictability is achieved. OEE control can also be achieved as predictability of maintenance completion approaches 90%.
Getting started: The completion-rate KPI really demonstrates the degree of overall maintenance control. Planning must be established and woven into the routine of all maintenance work. Planning of work must include accurate estimation of resources involved in executing work orders. This requires a closed-loop system for improving inaccurate estimates. Scheduling that is driven by accurate estimates and balanced against actual staff availability must follow. Weekly planning and scheduling meetings will be required to develop and publicize accurate schedules. Finally, each work order must be closed with the return of equipment to production, the documentation of lessons learned, and the return of maintenance resources for the next job.
Assessment of today’s situation: A chart of the above elements and a frank discussion of where the operation stands in the development of each will provide a good beginning.
A discussion of last month’s KPI, percent of emergency work, will help to clarify the connection between unplanned work and control of maintenance. Last month, we established that when emergency work exceeds 25%, half the maintenance crew cannot be intelligently scheduled. Game over for OEE.
Using today’s KPI, we would say that control of OEE requires that maintenance planning and execution run as a predictable routine 90% of the time. Control of maintenance requires that emergency work be reduced to about 5% of the workload. This means that OEE can only be managed if maintenance operates in a proactive mode. Reactive maintenance destroys OEE, creating a huge competitive disadvantage.
Listen for the dominos. They might be headed your way.