Overall Equipment Effectiveness (OEE).
An ideal situation is when in a factory equipment would operate 100 percent of the time at 100 percent capacity with an output of 100 percent good quality products. In real life such situations do not happen.
Losses are the reason between the ideal and the actual situation. It is crucial to calculate the overall equipment effectiveness rate to reduce equipment-and-processes related wastes through "Total Production Maintenance"(TPM), and with other methods like "Operational Excellence","Six Sigma", or "World Class Manufacturing".
What are the 'elements' in OEE?
Downtime, speed loss, and defect or quality loss are the three main categories of equipment related losses. These are also the main ingredients for determining OEE. The OEE is calculated by combining the three factors that reflect these losses:
Availability Rate is the time the equipment is really running versus the time it could have been running. A low available rate reflects downtime losses: a) equipment loss, b) set-up and adjustments
Available Rate = Operating time - downtime / Total operating time
Performance Rate is the quantity produced during the running time versus the potential quantity, given the designed speed of the equipment. A low performance rate reflects speed losses: a) idling and minor stoppages, b) reduced speed operation
Performance Rate = Total output / Potential output at rated speed
Quality Rate is the amount of good products versus the total amounts of products produced. A low quality rate reflects defect losses: 1) scrap and rework, 2) start-up losses
Quality Rate = Good output / Total output
OEE is calculated by multiplying the three factors together: OEE = availability rate x performance rate x quality rate.
The purpose of OEE is to improve the effectiveness of the equipment. Since they affect the shop floor employees more than anybody else, it is necessary for them to get involved in tracking OEE and in planning and implementing equipment improvements to reduce effectiveness loss
How OEE benefits the operators and Shifts In-charge or the line managers:
It is good for the operators to collect daily data about the equipment for use in OEE calculation. This will
The data will also give the line manager or Shift In-charge
There is, no doubt, OEE improves productivity on all fronts.