I am working on implementing OEE in one of our machines that makes centertubes for automotive oil filters. The steel is rolled and each part number has specific diameter and length. However, the run-rates vary for each part numbers. I am somewhat able to calculate Takt time for each part number based on the standard run-rate. However, the problem for me is to determine Ideal Cycle Time. The machine can run as fast as 65 PPM for one part number while it runs as slow as 13 PPM for some other part number. In this case, what would be the optimal way to calculate Ideal Cycle Time for each part numbers? As you know, Ideal Cycle time is required to calculate Performance Metric of OEE.