Overall Equipment Effectiveness (OEE) is a standard metric for measuring the productivity of any industry. It gives about the percentage of manufacturing time that is truly productive.
OEE is simply the product of Availability, Performance and Quality.
The World Class Manufacturers achieves a minimum OEE of 85 %.
OEE = Availability (A) * Performance (P) * Quality (Q)
Availability is the ratio of Actual Operating Time by Planned Operating Time. It takes into account Down Time Loss. Any event that stops the planned production affects the availability and should be reduced or eliminated. These down time can be due to change over time, equipment failures, material shortages etc.
Availability = Actual Operating Time / Planned Operating Time
Performance represents the speed at which the machine runs as a percentage of its designed speed. It takes into account of Speed Loss. The machine should be worked at its optimum speed as per design conditions. Any speed less than optimum speed reduce productivity.
Performance= Design Cycle Time/ (Actual Operating Time / Total Pieces)
Quality is the ratio of Good Parts Produced by Total Parts Produced. It takes into account Quality losses. It shows us about the parts that do not meet quality standards. Some parts become defective and some gets reworked and affects productivity. Our aim is to produce high quality parts right t the first time.
Quality = Good Parts Produced / Total Parts Produced