Understanding OEE
OEE
Understanding OEE
Overall Equipment Effectiveness
Metrics that go into the OEE formula
- Availability
- Performance
- Quality
OEE
OEE = Availability% x Performance% x Quality%
if:
- Availability = 91% (0.91)
- Performance = 98% (0.98)
- Quality = 99% (0.99)
then the OEE = 88% (0.88):
88% = 91% x 98% x 99% (0.91 x 0.98 x 0.99)
OEE is only calculated on available time.
Available time
In FactoryWiz, available time is time covered by a shift and when the machine was either in production or setup mode. So if you have 2 shifts 06:00-14:00 and 14:00-22:00 then you have 16 hours a day as available time.
The Availability metric
Availability = Running time / Available time.
So if a machine runs for 10 hours in a day, then the Availability is 62.5%:
10 / 16 = 0.625
The Performance metric
Performance = Average Planned runtime / Average Actual Runtime
If a machine was averaging 120 seconds or running per cycle but it should take 108 seconds, then the performance is 90%
108 / 120 = 0.9
Running time is NOT cycle time (cycle time includes idle and paused time).
What is the Quality metric?
Quality = Good parts / Total parts
If a machine makes 500 parts and rejects 30 parts then the Quality is 94%
470 / 500 = 0.94