Q: Should spillage be considered in OEE calculation?
Let’s say I’m producing 90 pieces instead of an expected 100. Then my OEE should be 90/100 = 90%. But now consider the conveyor is faulty because of which 10 pieces got spilled (without stopping the line). These 10 pieces spillage are waste as those can’t be use as finished goods. So 90-10 = 80 is my actual output now. In this case, my OEE should be 80/100 = 80% right?
Q: Sometimes our process is being interrupted; i.e. the oven is stopped at a different moment than planned. At that moment it is not clear whether the product will be OK or not. We will block the product and take samples to determine the quality. This could take a couple of days. Wen everything is OK the product is released, otherwise it is being scrapped. This would have a retrospective effect on the OEE I guess? A correct quality rate -and thus OEE- for the day is no longer possible in this way. What number should I now use?
Q: What is First Time Through (FTT) or First Time Right (FTR)?