Key Performance Indicators in Manufacturing Plant Maintenance

Why should you implement Key Performance Indicators (KPIs) in the maintenance program for your manufacturing plant? What are some typical KPIs in this field?

What is a Key Performance Indicator (KPI)?

Each KPI is a measurement of performance. An example is "How long does it take to do this task"? That question might be equivalent to "How many times does the employee perform this task in a week"?

The performance must be measured against a standard. It is not enough to know that it takes an hour; should it realistically only take 35 minutes, or does a thorough job really need three hours?

Also note the word "Key" in KPI. Many things might be measured, but not all are helpful. One shop may measure performance against schedule, so "all scheduled maintenance is completed without overtime" becomes the gold standard. However, that achievement might come at the cost of padded estimates and hiring extra staff to be sure there the schedule is met. Is this really the important metric? This should be restated as "scheduled maintenance tasks run no more than 5% over the performance standard", with realistic but demanding standards.

Here is another example to help distinguish a helpful KPI. Let's say that the standard scheduled preventative maintenance for one machine involves replacing a few inexpensive parts. A non-factory example would be changing the oil and filter in an automobile. This particular maintenance task will always require those items, so there should be little reason to track the materials cost separately. (A computerized system might note those as standard costs, or capture the reduction in inventory anyway). But in a manual KPI system, capturing the cost of these consumables might not be very helpful.
By contrast, if the maintenance task has a number of expensive discretionary parts, then it would be very important to track what was used. Not only should the variable costs be monitored, but if more parts than normal need to be replaced, then that might indicate a larger problem to be resolved.

The Key to "Key" is the Trigger for Action

The important question is: if the KPI is not achieved, would that trigger some corrective action? If management were to ignore the situation, then it is not a "key" indicator.

Conversely, if "something has to be done about it", then "it" should be measured in a KPI.

Benefits of Using KPI in Maintenance

The significant benefit of tracking KPIs is that missing the standard signals the need for change. For example, say that there is a standard for addressing a non-critical but unscheduled work orders. (The machine is still functioning, but the operator has a concern and wants it checked before the next scheduled maintenance cycle). A typical KPI would be that 80% of such work orders should be completed within 5 days. In the monthly review, if only 65% of such work orders were completed in that time frame, then management must take remedial action. (The analysis might find problems such as: a lack of spare parts; scheduling conflicts because of illness, other emergency repairs, or a large pre-scheduled maintenance project. The specific problem would then be addressed).

Another benefit is that the maintenance workers will have clear guidance on the standards they should meet. This should allow them to do their jobs well, without being rushed into making mistakes. At the same time, they know the level of performance that they have to meet.

By the same token, if the front-line production employees know the standards expected in the KPIs, they will be less likely to "cry wolf" and overstate problems in order to get attention.

Typical Examples of KPI in Maintenance

This is a brief list of some of the best KPIs for factory maintenance programs:

  • Labour time for specific scheduled maintenance tasks
  • Cost of maintenance and repair against depreciated capital cost, per machine
  • Cost of maintenance and repair against productive value (number of units or sales value, per machine
  • Failure avoidance, failure frequency, or mean time between failure (MTBF): a worsening in any of these measurements may indicate that scheduled maintenance should be increased or improved
  • Meeting the target response times to begin or complete unscheduled repairs
  • Completing scheduled maintenance tasks within the standard time
  • Track unexpected outages and costs by work order; by machine; by department
  • Overall Equipment Efficiency (or "effectiveness") measure: the machine's percentage of availability when it is scheduled to be working ("uptime"); its percentage of peak output achieved when running; its quality as the percentage of non-defective outputs; and possibly the load percentage compared to the number of hours the factory is working
  • Percentage planned maintenance versus the percentage of emergency repair work

The Costs of Tracking KPI

Every activity such as KPI comes with a price: someone has to take the time to log the activity, and then summarize the data and review it with management.

A CMMS (computerized maintenance management system) can help by tracking work orders, parts, labour and schedules. These functions are all available in a typical CMMS, and the maintenance manager should ensure that it is used consistently so it can capture all the data.

This introductory article explains CMMS in greater detail.

As noted in the previous section, the KPI process might use information such as the depreciated cost of a machine, or the average value of the products it makes. This data might not be available in a standard CMMS, or it may have been neglected as part of rolling out the CMMS project.

Implementing KPI

A project to set the KPIs for plant maintenance is significant but rewarding. It should be easy to focus a brainstorming session for each department, shop or type of machine. As well, consider what is important for scheduled preventative maintenance, emergency maintenance and the in-between unscheduled maintenance requests.

Track actual performance in order to set realistic and attainable KPI standards. Then hold yourselves responsible for meeting those standards.

You may also want to read about Reliability Centered Maintenance ] and Kaizen: An Introduction to Continuous Improvement.

By Oskar Olofsson