At its core, OEE or Overall Equipment Effectiveness is so much more than just another metric. It’s one of the best opportunities you have to truly measure the current manufacturing productivity – and ultimate potential – of your lines.
By making an effort to proactively measure OEE, you gain a better understanding of your underlying losses than ever before. At that point, you have everything you need to consistently improve your manufacturing processes across the board.
Yet at the same time, there are a number of common misunderstandings that people have concerning OEE and, more importantly, why they should care so much about it. Clearing up the confusion surrounding these areas therefore puts you in the best position to extract as much value from this measurement as possible.
Overall Equipment Effectiveness: Breaking Things Down
One of the biggest misconceptions about OEE is that it’s actually possible to somehow achieve a perfect score of 100% at all.
Keep in mind that if you had an OEE score of 100%, it would mean that you were manufacturing A) only top-quality parts, B) as quickly as you could, C) with absolutely no stop time to speak of. To say that this is unrealistic in real world conditions is putting things mildly.
Every manufacturing lines will have certain products that need to be reworked. Machines will have to go down for maintenance. Employees need to change shifts. All of these things need to be factored into your OEE score not so that you can get it to 100%, but so that you can meaningfully improve it whenever the opportunity arises.
So if you perform your OEE measurement and don’t get a perfect score, don’t worry – that really isn’t the point. The point is that OEE is a way to benchmark your progress, to eliminate waste and to improve the productivity of your manufacturing equipment as much as you realistically can.
Along the same lines, another common misconception that some people have is that it’s possible for an OEE score – or any of the underlying metrics – to actually exceed 100%. This, too, is false – and it also highlights what is likely a problem in the methods you’re using to calculate these metrics to begin with.
Again – if you were able to in theory hit an OEE score of 100%, it would mean that you were tapping into the full potential of your production lines with absolutely no waste to speak of. How, then, would you be able to make things better from there? You could always increase the speed at which parts are coming off of your lines, but the chances of that not impacting the other calculations in some way are slim-to-none.
If you go through the trouble of calculating OEE and you arrive at a score that is over 100%, this means that one of the metrics – either availability, quality or performance – are being incorrectly measured. It could also point to a situation where one of these factors is improperly defined.
In a lot of cases, businesses have an incorrect interpretation of what their “performance” metric is really counting. Their ideal cycle time is usually set too high, which brings their performance score higher than 100% and throws off the accuracy of the rest of the calculation, too.
In the end, OEE is an invaluable way to improve the performance of your manufacturing lines – but you have to understand what it’s telling you and, more importantly, what it isn’t. Only then will you be able to use it as the basis for continuous improvement moving forward.