OEE, Overall Equipment Effectiveness, captures the percetage of time that equipment, when running or required for production, is producing good-quality product at an acceptable rate. It is calculated by multiplying the availability rate by the production rate by the first-pass yield.
On the shop floor, OEEE can be measured hourly and gives the on-site manager a real-time look into productivity. It also has the advantage of limiting a drop in productivity to one of three factors: machine up-time, machine speed, and production quality. If the machine was not down during the hour, then there is a problem is with either the speed or quality. If the machine/process speed is within the acceptable range, then there is a problem with quality. And if there is a problem with quality, either a machine is malfunctioning or a worker is not producting up to par. If, after testing each machine, it is found that machines are working within acceptable parameters, then a worker needs more oversight or training.
In addition, according to a recent article in Industry Week, it can help to eliminate ‘silo’ thinking as the manufacturing process is measured as a whole, and not a system of discrete steps. However, if misunderstood, OEEE can promote “over production” as any increase in the production rate without a(n unacceptable) decrease in quality or machine availability improves the metric, and this is often the easiest path to metric improvement.
So how important is (revisiting) OEEE to your Performance Measurements? At the plant level, it is certainly important. However, at the Supply Management level, it’s more about the value generated from manufactured goods, which depends on their ultimate cost and ultimate sale price. Thus, if costs go down and revenue goes up when less produt is manufactured and an artificial scarcity is created, then a lower OEEE might be desired. But if costs go down and revenue goes up when the market is flooded, then a high OEEE might be desired. While maintaining an OEEE in an efficient range is desirable, it’s probably not the most important metric in the Supply Manager’s toolkit.