“Overall Equipment Effectiveness”, known in the jargon as “OEE”, is a composite metric which quantifies how far a factory is from its optimal performance – the performance level for which it was designed to.
OEE is an aggregation of three separate factors:
- Availability - Represents the percentage of the scheduled time that the operation has to operate.
Formula= Uptime / Available Time
Operational Time = 450 Scheduled Min – 60 Non-Scheduled Downtime Min = 390 Minutes
Availability = 390 Minutes / 450 Minutes = 86,6%
- Productivity - The speed at which each work center works as a percentage of the optimal productivity for which it is designed to.
Productivity = (Parts Produced * Optimal Cycle Time) / Produced Time
Time to produce units = 242 Units * 1,5 Minute/Unity = 363 Minutes
Productivity = 363 Minutes / 390 Minutes = 93,0%
- Quality - The good units produced as a percentage of all the units started.
Quality = (Units Produced – Defective Units) / Units Produced
(242 units produced – 21 defective units) = 221 good units
Quality = 221 good units / 242 units produced = 91,32%
In these examples:
OEE = Availability * Productivity * Quality = 86,6% * 93,0% * 91,32% = 73,55%