OEE Software
Overall Equipment effectiveness (OEE) is a helpful statistic used to measure how well a particular manufacturing process is doing. OEE condenses several factors into a single value. That value tells you at a glance how well things are going. OEE is the product of key metrics for a manufacturing process that are recorded, timed, and planned.
The Three Major Components of OEE
Vocab Terms
The terms are often used but depending on context can have very different meanings. Before discussing the way to calculate these components we must first understand some common definitions related to overall equipment effectiveness.
Cycle Time- the time it takes to go complete one cycle.
Idle Time- the time spent between cycles
Fault Time- is the time spent when a fault, code, alarm, etc. is thrown and stops a cycle.
Stop Time- is the sum of all the time spent not processing.
OEE Is comprised of three major components.
Availability
Performance
Quality
They are all decimal values ranging between 0.0 and 1.0. To calculate OEE simply multiply all three values together:
OEE= Avialbility x Performance x Quality
Calculating the Major OEE Components
How to Calculate OEE
We now come back to the equation for OEE:
OEE= Availability X Performance X Quality
Which can be expanded to:
Availability
Availability, also known as uptime, is the amount of time the machinery was running (Run Time) divided by the amount of time the machinery was scheduled to run (Planned Production Time).
Recall:
RunTime = PlannedProductionTime − StopTime So, alternatively, this equation will also yield Availability:
Performance
Performance is the theoretically shortest amount of time to process everything divided by the recorded amount of time spent processing everything. Over the course of the PlannedProductionTime, multiply the CycleCount by the IdealCycle Time and divide by the Run Time.
Recall:
RunTime = PlannedProductionTime − StopTime So, alternatively, this equation will also yield Performance:
Quality
Quality is the cycles without faults divided by all cycles (Cycle Count).
The following are the core building blocks of OEE. With these, we are able to derive the major components:
Planned Production Time
Run Time
Ideal Cycle Time
Cycle Count
Fault Count
Note: The first three time metrics will be time durations. To ensure calculations are accurate, a consistent unit of time must be kept. Such as days, hours, minutes, seconds, etc.
4.1 Planned Production Time:
This is the amount of time or duration scheduled for processes to take place. Another way to think of this is the total time spent attempting to complete cycles.
4.2 Run Time:
This is the amount of time spent while the process was actually taking place. Run time can be thought of as the difference between planned production time and stop time.
RunTime = PlannedProductionTime − StopTime
4.3 Ideal Cycle Time:
For a given process, this is the ideal time it would take to totally complete. This does not include time between cycles (Idle time) or any other stop time.
4.4 Cycle Count:
Over the course of the planned production time, this is how many cycles were completed. The value here is a whole number.
4.5 Fault Count:
Over the course of the planned production time, this is how many cycles experienced an error code, alarm, quality issue, equipment failure, etc. The value here is a whole number.
Five Minor components of OEE