3.1: Learning About Maintenance Metrics
You can only improve what you measure. Therefore, tracking maintenance metrics is a vital component of achieving world class maintenance in your organization. But not every maintenance metric is of equal importance to every company. Metrics that qualify as key performance indicators (KPIs) are dependent on your industry, your company’s goals, and the types of assets you manage.
Instead of placing equal importance on every metric you track, choose a few KPIs. You can also choose a few “leading indicators” that help you determine why KPIs are getting hit or being missed. For instance, if schedule compliance is a KPI, “percentage of work covered by a work order” may be a leading indicator.
Below, we explore different maintenance metrics that you can track as KPIs and leading indicators.
There are different metrics that maintenance and production teams use to track the reliability of equipment.
Unscheduled downtime: This results from unforeseen breakdowns and requires work orders that are not scheduled out in advance. It is a variation of the metric called “planned maintenance percentage” that’s discussed below.
World class unscheduled downtime: 10% or less
Equipment availability: This is a measure of how often a piece of equipment is available for its intended purpose. Unscheduled downtime detracts from availability, as well as various types of preventive maintenance. However, the latter is necessary to increase equipment availability in the long term.
World class equipment availability: 90% or greater
Uptime percentage: This is a high-level metric that you can easily track in your CMMS. When the equipment is down, operators or technicians can mark it as non-operational from a mobile CMMS app. This time is calculated into the uptime percentage by the CMMS. Managers can also add downtime manually. (Uptime is often synonymous with availability.)
World class uptime availability: 90% or greater
Maintenance backlog is a measure of required maintenance work that has not yet been completed. Some backlog is healthy as it indicates that there are not overstaffing issues within a facility. Too much backlog, on the other hand, can lead to a surplus of deferred maintenance which is not good.
World class maintenance backlog: ~2 weeks worth of tasks per technician
Mean time between failure (MTBF) is a maintenance metric that defines the average time that equipment is operating between breakdowns or stoppages. This intuitively relates to the availability of the equipment. Availability, also known as uptime, is one of the key indicators of overall equipment effectiveness and is always a focus area for improving productivity.
World class MTBF: Varies based on equipment type
Mean time to repair (MTR) is the average time it takes for equipment to be diagnosed, repaired, and recovered after experiencing a failure. By keeping a data-driven mindset and proactively improving the MTR, the manufacturing processes can reduce availability losses due to repairs. The idea is to speed up the equipment’s rate of recovery from failures and breakdowns.
World class MTR: Varies based on equipment type
Overall equipment effectiveness (OEE) is a standard used for measuring plant performance. OEE is used as a gauge to assess how well the plant is performing. Three main factors drive the plant’s performance: availability, performance efficiency, and rate of quality products.
World class OEE: 77% or greater
Planned maintenance percentage (PMP) is a percentage that describes the amount of maintenance time used towards planned maintenance tasks, which is measured against the total amount of maintenance hours in a given time period (weeks, months, years).
World class PMP: 85% or greater
Schedule compliance is a maintenance metric that measures the percentage of time that scheduled work orders are completed. Organizations that are committed to measuring the effectiveness of their scheduled maintenance process use schedule compliance as a performance metric.
World class schedule compliance: 90% or greater
Other Maintenance Metrics
- Maintenance cost as a percent of RAV is a metric that shows how cost-effective your maintenance efforts are, where RAV stands for replacement asset value. One percent is considered world class.
- Average days to complete work orders may be used to determine whether a maintenance team is becoming more productive. However, this should be measured alongside failure-related metrics to ensure that faster maintenance doesn’t result in more failures.
- Percentage of work covered by a work order shows how much maintenance activity you’re logging in your maintenance software. In addition to helping measure data acquisition efforts, this metrics also measures a maintenance team’s degree of organization. The goal is to reach 100%.
- Maintenance overtime helps you understand whether you need more people on your maintenance team. Having a little overtime is good, but having too much can lead to employee burnout and excessive labor costs. The goal is to achieve around 5 percent.