Maintenance key performance indicators (KPIs) measure critical factors that directly impact your organization’s success. An important metric in the maintenance world is Overall Equipment Effectiveness (OEE) and the OEE calculation, which measures how effectively each piece of equipment in your organization is used.
Learn more about what OEE is, how to calculate OEE, and how to improve this KPI in your own facility:
What Is OEE in manufacturing?
As a best practices metric, OEE helps manufacturers determine how much of their production time is actually productive. As the name suggests, Overall Equipment Effectiveness (OEE) evaluates how effectively your equipment is running by measuring equipment against three factors: Availability, Performance, and Quality.
How long was the process actually running relative to the planned production time? Were there any planned and/or unplanned stops? An availability score of 100% means the machine ran continuously throughout the planned production time without stopping at all.
How fast is the process relative to your ideal cycle time? Was the process slowed down by any slow cycles or small stops? A performance score of 100% means the process ran as fast as possible relative to its ideal cycle time.
Were there any production defects? Did any parts require rework? A quality score of 100% means there were no defects in any parts produced.
Each of the individual scores above then roll up into the overall OEE score, which takes into account the losses experienced in each area. An OEE score of 100% means that the machine ran as fast as possible, with no downtime, and no defects.
OEE Calculation Example
Now let’s put OEE into practice with the following example:
Run Time / Planned Production Time = Availability %
For example, your asset was expected run for 300 minutes, but because of an unexpected maintenance issue, it went offline for an hour for repairs. This resulted in an actual run time of 240 minutes during the planned production period.
The result: 240 minutes / 300 minutes = 80% Availability
(Ideal Cycle Time x Total Count) / Run Time = Performance %
For example, your asset is expected to yield a total of 200 units with an ideal cycle time of 1 minute per part. The run time of the shift was 240 minutes, and the machine produced 150 units in that time.
The result: (1 x 200) / 240 = 83.3% Performance
Good Count / Total Count = Quality %
In the last section, your machine produced a total of 150 units; however, because of errors in the process, the result was 110 good units with no defects.
The result: 120 / 150 = 80% Quality
OEE takes all of these elements into account, factoring in all losses.
The result: Availability (0.8) x Performance (0.833) x Quality (0.8) = 53.3% OEE
What Is a Good OEE Calculation Score?
The OEE calculation example above yields a score of 53.3%. Is that good or bad? And how do you know? The answer depends on both your own facility’s baseline (is this number an improvement or degradation compared to previous scores?) and industry benchmarks (is this number higher or lower relative to industry standards?).
Current OEE Score vs Facility Baseline
As with any maintenance metric, OEE is a performance indicator that will change over time. With a CMMS software, you can easily track scores over time, pinpoint where and why production losses occur, and identify areas of focus.
Thus the above example OEE score of 53.3% is a bit lower than typical, leaving potential opportunities for improvement in all three OEE factors.
Improving OEE With a Computerized Maintenance Management System (CMMS)
One of the best ways to track maintenance KPIs such as OEE is by using Computerized Maintenance Management System (CMMS) software. With a CMMS, you can easily establish baselines, measure performance, and identify opportunities for improvement. Using a CMMS such as eMaint can be the difference between your organization exceeding or falling short of its maintenance KPIs.
Contact us to learn more about how eMaint can help you improve your maintenance KPIs.