“Schedule compliance” or “Adherence to schedule” is a commonly-used Maintenance KPI (Key Performance Indicator) and is a measure of how much of the maintenance work scheduled for a maintenance crew, usually in one week, is actually completed in that time.
On the face of it, this leading KPI should be a measure that tells people who request maintenance work how much confidence they can have that it will be done as scheduled. However, Schedule Compliance can easily be mis-used and can have some serious unintended and undesirable consequences.
It is sometimes assumed that a low schedule compliance is solely the result of “break-in” work, i.e. work that was not scheduled and was considered important enough to interrupt the schedule. However, there are other factors that affect schedule compliance, including:
– unscheduled absences
– maintenance work that takes more or less time than is estimated which could well be most maintenance work especially if work orders are not well planned.
The alternative to measuring Schedule Compliance is to record unscheduled work that is done and such a record may be a more useful KPI, as explained below.
The nine principles that guide the development and selection of KPI’s are:
- KPI’s must encourage behaviour that is in the best interests of the organization (not just Maintenance)
- They should be difficult to manipulate
- They should be easy to measure
- They should be “balanced”
- They should be consistent
- They should provide enough information to show a trend
- The measurement process should not affect the measurement
- They should be achievable
- The information gathered should indicate the action that should be taken to correct unfavourable differences between the KPI measurement and the target.
Let’s look at how Schedule Compliance and Unscheduled Work Recording stack up against each of these principles.
- Encourage the right behaviour.
This is one principle where Schedule Compliance is very weak.
As an example – during a visit to a client that was using Schedule Compliance as their only important leading Maintenance KPI, I asked the Electrical Superintendent what the schedule compliance was for his crews, and he answered “over 90%”. Later in my interview I asked how much work that was done was not on the current weekly schedule, and the answer was “about 50%”. I wondered how that could be, until I looked at the weekly schedule.
One of the first jobs on the schedule was to lubricate 7 electric motors. Two electricians had been scheduled for this job for 7 hours each, a total of 14 man-hours. Now greasing electric motors must be done carefully, but even if the motors were fitted with grease drains, in my estimate this was a job that a single properly trained electrician could have completed in 2 hours at the most, and probably much less. (As an aside, I noted that each item of equipment that the 7 motors were driving was lubricated by a single lube mechanic. Bad habits, such as assigning two electricians to every job, are easy to get into and very hard to break. As an ex maintenance manager, I must admit to having been guilty of ignoring some of these kinds of established bad habits.)
While this is a gross example of over-estimating maintenance work, it is indicative of what can happen if there is too much focus on schedule compliance and not enough on getting the work done.
Another serious effect of focusing on schedule compliance is that legitimate urgent work may be delayed when it should be done immediately, because it will adversely affect the schedule compliance for the week. An over-riding principle should be that the most urgent work is always done first, whether its scheduled or not.
I’ve heard it said that the best way to get more work done is simply to schedule more work and so long as this takes the form of setting reasonable expectations I believe it to be true. If it is true, then scheduling to achieve a high schedule compliance is in direct conflict with getting more work done so the “schedule compliance” KPI can strongly encourage undesirable behaviour.
On the other hand, unscheduled work can not be anticipated and is not affected by estimating errors, absences, etc so a record of this work does provides information for improving maintenance performance.
- Difficult to manipulate
As explained above, schedule compliance is very easily manipulated by over-estimating work orders.
The number of unscheduled jobs can be manipulated by executing them under standing work orders or other open work orders or by delaying them until they can be scheduled when they really should be done immediately, so this KPI also needs to be well managed.
- Easy to measure
Schedule compliance is very easily measured and some maintenance computer systems will include this KPI as a standard report.
Unscheduled work orders are also easily measured, and may be defined as any work order where hours are charged in the same week that the work order was originated.
- KPI’s should be balanced
Any KPI should be assessed by considering, and measuring, the effects of very high or very low results. For example, if there is a KPI to reduce Stores inventory the effect of too great a reduction may be an increase in downtime. The downtime caused by the unavailability of spare parts should be measured as a balancing KPI to inventory reduction.
There is no strong balancing KPI for schedule compliance, but measures that indicate that less work is being done, such as the material:labour ratio, could be considered.
One common problem is that only one of two balancing KPI’s is easy to measure, as is the case with the total Stores inventory. Care should be taken not to place too much emphasis on a KPI just because it is easily measurable.
- They should be consistent
This means that a high measured value is consistently desirable or consistently undesirable. For example, if overtime is a KPI, and overtime during normal operation is considered “bad” while overtime during a major planned shutdown is considered “good” it is inconsistent to combine them into a single measure of total overtime.
Consistency is not an issue with schedule compliance or unscheduled work.
- They should provide enough information to show a trend
Schedule compliance and recording unscheduled work both provide ample information for trending.
- The measurement process should not affect the measurement
Because work is scheduled by people who will be judged by the resulting schedule compliance, the measurement process can strongly affect the results.
8. They should be achievable
If a challenging schedule is the objective, 100% compliance to that schedule is unlikely to be achievable or desirable in a typical manufacturing operation.
9. The information gathered should indicate the action that should be taken to correct unfavourable differences between the KPI measurement and the target.
Schedule compliance is reported as a single number and it is of very little use in determining the action to take to address low results. It is about as useful as reporting the average speed of vehicles in a city in an effort to reduce speeding. The action must address the individuals. The single obvious action that can be taken to improve schedule compliance is to schedule less work, by overestimating work orders.
On the other hand, reporting the unscheduled work orders (excluding small jobs) is very useful. Each event can be evaluated and very specific actions can be taken to reduce future unscheduled work. These actions can include:
– addressing reliability issues on equipment that fails unexpectedly by improving PM inspections, redesign, etc.
– addressing the late submission of work orders for problems known to exist.
– ensuring that the priority-setting process is being followed.
– ensuring that everyone in the organization, including shutdown coordinators, trainers and managers, respect the weekly scheduling process and ensure that schedulers are aware of all events that will reduce the availability of tradespeople well in advance of preparing the weekly schedule.
Schedule Compliance is a very weak leading KPI and unless it is very carefully managed it will have negative consequences. If Schedule Compliance must be used, managers should carefully study all work schedules and make sure that the estimates are challenging. This is a difficult and time-consuming process because it requires that the scope of each work order is thoroughly understood.
On the other hand, examination of unscheduled work can result in very fast feedback and has the potential to quickly improve overall Maintenance performance as measured by the two basic lagging KPI’s – reliability and costs.
Related articles:
– Maintenance performance measurement – the hazards in KPI’s
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Don Armstrong
Veleda Sevices Ltd