Overall Equipment Effectiveness (OEE)
The key factor used with respect to these factors is equipment effectiveness, defined as follows:
Overall Equipment Effectiveness is the effective utilization of the equipment on the whole so that the desired productivity is achieved at a certain quality level and is mathematically expressed as the product of Equipment Availability, Performance Efficiency and the Rate of quality.
Overall Equipment Effectiveness (OEE) = Machine Availability × Performance Efficiency × Rate of Quality
Or = A . η. Ro Q
Where
Equipment Availability (A) = Available Time/ Planned Time
=( Planned Time - Down Time )/ Planned Time
Performance Efficiency (η) = Theoretical Cycle Time/ Actual Cycle Time
Rate of Quality (Ro Q) = Accepted Quantity/ Produced Quantity
Thus, OEE = (Planned Time - Down Time/ Planned Time) × (Theoretical Cycle Time/ Actual Cycle Time) × (Accepted Quantity/Produced Quantity)