What is PM compliance and why is it important?

The meaning and interpretation of Preventive Maintenance (PM) compliance can vary depending on the specific industry. In the upcoming article, when we discuss PM compliance, we are referring to the measure of how effectively preventive maintenance tasks are executed on time according to maintenance’s schedule.

Additionally, when we mention PMs in this article, we are specifically discussing PM rounds, which are combinations of multiple preventive maintenance tasks grouped together to form a complete PM round.

The following lines will elaborate into the significance of this metric while also addressing its limitations and explaining why it should not be the sole key performance indicator (KPI) that your plant uses for assessing PM performance. 

1. PM Compliance

When discussing PM compliance metrics, this metric is typically expressed as a percentage, representing the ratio between the number of completed PMs and the number of scheduled PMs:

To calculate PM compliance, you need to establish a specific time interval that provides a common basis for both variables. Often, this analysis is conducted over a period of one week or one month. To illustrate the calculation, consider the following example: if a planner aims to complete 25 PM routes within a week but the team manages to accomplish only 17 of them, the PM compliance would be:

PM compliance enables an objective assessment of your maintenance team’s performance in comparison to the originally planned preventive maintenance. However, if your plant intends to use PM compliance as a measure for assessing the overall performance of your PM team and the effectiveness of your PM program, it is essential to recognize the limitations of this calculation.

That being said, the following lines will illustrate its limitation, both due to the calculations itself and external parameters and what can be done to address them. Note that when external factors influencing this calculation are controlled, PM compliance will be an accurate indicator of the performance of your PM program and team.

2. Limitation of PM Compliance:

Focusing solely on PM compliance is a positive step towards objectively quantifying preventive maintenance activities at your plant; nevertheless, it does come with certain limitations. Here’s a list of the four main limitations associated with PM Compliance:

2.1 Over-scheduling issue:

To begin with, consider the scenario where the scheduled workload exceeds the available workforce capacity. For instance, in the situation mentioned earlier, if there are 25 PMs scheduled, requiring 55 hours of work, but you only have 40 hours of available workforce for the week, the maintenance team may fully utilize their available time, yet the resulting PM compliance could be as low as 68%. That being said, is it fair to say that the PM team performed at 68%?

2.2 Underestimation:

Next, let’s consider a comparable situation. Imagine your planner schedules 40 hours of preventive maintenance for the available 40-hour workforce in a week. Theoretically, everything appears to be in order. However, as the PM team starts performing the PM tasks, they soon realize that the estimated hours for completing the work were significantly underestimated. In reality, fulfilling all the PMs would demand 80 hours, resulting in the PM team completing only half of their schedule and yielding a 50% PM compliance. Does this imply that your PM team is only 50% compliant?

2.3 Tasks compliance:

In the third scenario, consider a situation where your PM successfully completes all 25 scheduled PM rounds for the week. However, within those PMs, certain tasks couldn’t be executed due to equipment inactivity, unsafe conditions, or ongoing repairs, among other reasons. Despite achieving a 100% PM compliance, technically, a substantial number of assets remain unattended, and this aspect is not reflected in the PM compliance metrics. Again, this raises a question – is it fair to say that the PM performed 100% of its work?

2.4 Maintenance strategies compliance:

Lastly, as previously mentioned, PM compliance is defined as the ratio of completed PMs to scheduled PMs. Consider a specific type of PM, such as oil-level inspections for critical gearboxes. According to your maintenance strategy, this PM should occur monthly, totaling 12 times a year.

Therefore, every fourth week, your planner does his best to try to include this PM in the scheduled program. Due to factors like planned shutdowns, employee vacations, and reactive corrective work orders, the planner can only schedule this PM 10 times a year. In each instance this PM is scheduled and completed, it results in a 100% PM compliance.

Nonetheless, when assessing the overall work completed compared to the maintenance strategy, the actual completion rate of the maintenance strategies is 10 out of 12, equivalent to 83%. This represents another factor that remains unaccounted for in PM compliance metrics.

3. How can you address and control those limitations?

3.1 Over-scheduling issue:

Regarding over-scheduling issues, when monitoring PM compliance, a systematic procedure is essential to always be aware of the updated available workforce allocated the preventive maintenance (PM). While it may seem obvious, PM work planning must align with the availability of dedicated preventive maintenance personnel.

Surprisingly, from our experience, in some instances, planners assume rather than verify the availability of PM workforce before scheduling, resulting in pour PM compliance. This is primarily a result of deficient planning processes, rather than the performance of the PM team.

3.2 Underestimation:

Regarding the second aspect of obtaining precise PM duration estimates, numerous solutions can be implemented to tackle this challenge. We recommend implementing a time-tracking tool that autonomously records the duration of PMs, recording time from starting the walk to location of the first task to the completion of the last one.

By accumulating multiple records of previous PM durations, you can calculate an average execution time and make precise adjustments to PM durations within the planning and scheduling system. This ensures that the PM team can realistically achieve the highest level of PM compliance and that a PM compliance of 100% isn’t out of reach.

3.3 Tasks compliance:

In addressing the third aspect concerning tasks performed during PM rounds, we proposed tracking an additional metric related to PM compliance: “tasks compliance.” The calculation for tasks compliance is as follows:

Tasks compliance will therefore be calculated for every PM round. Over time, this indicator will help to identify which PM routes actually bring value to the Preventive Maintenance program.

Furthermore, when PM activities are limited, this metric will be useful to prioritize PM routes that have a high tasks compliance because it shows that these are the ones that have historically shown to be bring the most value.

3.4 Maintenance strategies compliance:

Finally, when it comes to evaluating the overall accuracy of the maintenance strategies, we recommend monitoring a third metric, which is quite straightforward and referred to as “maintenance strategies compliance.” Typically, this metric is examined over an extended time frame, often spanning an entire year.

Example:

4. What to aim for?

Although benchmarks of specific industries help in locating where you stand compared to other organizations in your industrial domain, we often see the following for world-class companies:

• PM compliance: 85%. Aim 100% for top critical equipment and lubrication.
• Tasks compliance: >90%. Aim 100% for top critical equipment and lubrication.
• MS compliance: >85%. Aim 100% for top critical equipment and lubrication.

5. Frequencies adjustment

Bear in mind that tasks frequencies should be dynamically adjusted through time. For example, if you are measuring the deflection of drive belts every 3 months and have only changed one belt in the past 2 years, it might be wise to change the inspection frequency to 4-5 months. This will free up resources to focus on more critical tasks and help achieve higher rates of schedule compliance.

Conclusion

As mentioned earlier, monitoring PM compliance serves as an essential initial step in assessing the performance of your PM program. However, as detailed previously, it comes with a significant number of limitations. This is why we highly recommend integrating PM compliance with Tasks Compliance and Maintenance Strategies Compliance. By doing so, you can achieve several benefits. In the short term, it enables you to evaluate the efficiency of your PM team and program. Over the long term, these metrics facilitate the optimization of your maintenance strategies as time progresses.

Indeed, these three parameters provide the capability to pinpoint tasks that are either performed excessively due to the absence of findings within defined intervals or due to excessive inspections of equipment that is rarely available. Such tasks can then be optimized, and their frequency extended. On the other hand, having this data also aids in tracking equipment that isn’t inspected frequently enough because each inspection reveals potential failures, necessitating adjustments to the maintenance strategies.

Furthermore, it’s important to note that while we have discussed PM compliance, it’s equally crucial to consider tracking these same key performance indicators for Predictive Maintenance (PdM) technologies as well. Indeed, the same limitations are applicable for PdM compliance, and we also recommend adapting your analysis and calculations with the four parameters and recommendations listed above.