Overall Equipment Effectiveness is a standard measure for the productivity of equipment/assets. It measures the percentage of scheduled manufacturing time that an asset is fully productive. There are three sub-components of OEE: Availability, Performance and Quality.
The following terms are used to describe different elements of OEE calculations
Plant operating time: The time that the plant is open and available for equipment operation. Plant operating time = Sum of shift duration
Excluded time: Any period that should be excluded from efficiency calculations because the equipment is not intended to run. Examples are factory shutdowns and no demand. Excluded time = Sum of duration of asset status logs where status of class "Excluded"
Planned Time: Planned Time = Plant Operating Time - Excluded Time
Down Time: Any event that stops production during planned time. Examples: Breakdown, changeover, material shortage. Downtime = Sum of the duration of asset status logs where status of class "Downtime"
Run Time: Run Time = Planned Time - Downtime
Recovered Time: The duration equipment would have taken to produce the total quantity produced if operating at standard speed. Recovered Time = Quantity Produced * workcentre cycle time
Rework Time: Time booked to rework
Production Time: Production Time = Recovered Time + Rework Time
Speed Loss Time: The time lost due to a machine not producing at its rated speed. Speed Loss Time = Run Time - Production Time
Quality Loss Time: The time lost because a machine has made material that is reworked or subsequently rejected. Quality loss time = Sum of recoveries of material that has been scrapped + Rework time
Fully Productive Time: The time spent producing good quality output. Fully productive time = Production Time - Quality loss time
Availability: Availability (AV) = Run Time / Planned Time
Performance: Performance (PE) = Production Time / Run Time
Quality: Quality (QU) = Fully Productive Time / Production Time
OEE: OEE = AV * PE * QU = Fully Productive Time / Planned Time
