The 5 Most Important Maintenance Metrics to Track (and 3 Vanity Metrics to Avoid)
A good maintenance process is one that is steeped in data. Data should power your decision to do X, inform your approach to Y, and justify the cost of Z. The problem is, with all this data floating around, outcomes can become convoluted. It’s why world-class manufacturers rely on a defined set of metrics to help govern their maintenance and repair programs. Metrics take scattered data and distill it down into meaningful reports that inform action.
Unfortunately, like the never-ending sea of data, there’s also a wide swath of maintenance metrics to consider. Rather than track them all and try to derive infinite conclusions from them, manufacturers are better off starting with a select few metrics and improving from there. Here are five of them.
1. Overall Equipment Effectiveness (OEE)
availability x performance x quality = OEE
This is the measurability of the productivity of a piece of equipment. It factors in production quality, performance, and availability, giving maintenance managers a comprehensive understanding of the effectiveness of machinery. If you’re operating at 100% OEE, it means you’re producing as fast as possible, with no defects and no stops.
2. Mean Time to Repair (MTTR)
sum of downtime periods / total number of repairs = MTTR
This metric is the amount of time it takes to actually complete repairs — or, in other terms, the average downtime of equipment. Strive to make this number as low as possible by executing planned maintenance and thoroughly prepping any maintenance or repairs. Don’t compromise quality for quickness, though, or it could affect the next metric on this list: MTBF.
3. Mean Time Between Failure (MTBF)
sum of operational time / total number of failures = MTBF
This is the uptime between periods of downtime. Converse to MTTR, this number should be as high as possible, indicating sustained performance for as long as possible. If your MTBF is low, it suggests improper maintenance or an inefficient maintenance schedule. Measure and track this metric to adjust your maintenance approach at a granular level.
4. Maintenance Backlog
number of outstanding and overdue maintenance jobs in the queue
The larger your maintenance backlog, the more susceptible your equipment is to downtime. A large maintenance backlog means equipment is overdue for service and you’re operating on borrowed time. It also can indicate everything from staffing issues to component availability, signaling the need for improvement in everything from hiring to training, inventorying to maintenance scheduling.
5. Unscheduled Downtime/Unplanned Maintenance
number of incidents of downtime that are unplanned
Aside from tracking downtime for each machine, track how many times unscheduled downtime occurs. Each instance of unplanned downtime is a disruption to your value stream, which costs you far more than an investment in repairs. Delve deeper into this metric to discover anything from defective equipment, to lackluster maintenance, to failures caused by external variables.
Be careful of vanity metrics
Vital maintenance metrics go far beyond the above five examples. But be wary of tracking metrics for the sake of tracking metrics and harvesting data. Ask yourself, “what does this metric tell me?” It should immediately provide insight into actionable improvements and deliver a status-quo look at your operations.
Maintenance spend, for example. While it’s nice to say “our maintenance budget is down $2,000 from last year,” that metric means nothing unless it has context. If your MTBF has gone up as maintenance spend has gone down, that’s great! But, if your backlog has gone up, that’s less-than-great. Track these vanity metrics, but contextualize them before you lean on them.