OEE = Availability x Performance x Quality
Example:
A given Work Center experiences...
Availability of 86.7%.
The Work Center Performance is 93.0%.
Work Center Quality is 95.0%.
OEE = 86.7% Availability x 93.0% Performance x 95.0% Quality = 76.6%
Availability
The Availability portion of the OEE Metric represents the percentage of scheduled time that the operation is available to operate. The Availability Metric is a pure measurement of Uptime that is designed to exclude the effects of Quality, Performance, and Scheduled Downtime Events.
Calculation: Availability = (Available Time) / (Scheduled Time)
Example:
A given Work Center is scheduled to run for an 8 hour (480 minute) shift.
The normal shift includes a scheduled 30 minute break when the Work Center is expected to be down.
The Work Center experiences 60 minutes of unscheduled downtime.
Scheduled Time = 480 min - 30 min break = 450 Min
Available Time = 450 min Scheduled - 60 min Unscheduled Downtime = 390 Min
Availability = (390 Avail Min) / (450 Scheduled Min) = 86.7%
Performance
The Performance portion of the OEE Metric represents the speed at which the Work Center runs as a percentage of its designed speed. The Performance Metric is a pure measurement of speed that is designed to exclude the effects of Quality and Availability.
Calculation: Performance = (Actual Rate) / (Standard Rate)
Example:
A given Work Center is scheduled to run for an 8 hour (480 minute) shift with a 30 minute scheduled break.
Available Time = 450 Min Sched - 60 Min Unsched Downtime = 390 Minutes
The Standard Rate for the part being produced is 40 Units/Hour
The Work Center produces 242 Total Units during the shift. Note: The basis is Total Units, not Good Units. The Performance metric does not penalize for Quality.
Actual Rate = 242 Units / (390 Available min / 60 min/hr) = 37.2 Units/Hour
Performance = (37.2 Units/Hour) / (40 Units/Hour) = 93.0%
Quality
The Quality portion of the OEE Metric represents the Good Units produced as a percentage of the Total Units Started. The Quality Metric is a pure measurement of Process Yield that is designed to exclude the effects of Availability and Performance.
Calculation: Quality = (Good Units) / (Units Started)
Example:
A given Work Center produces 230 Good Units during a shift.
242 Units were started in order to produce the 230 Good Units.
Quality = (230 Good Units) / (242 Units Started) = 95.0%
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