Test/ Repair Loop: Potential Value Stream Bottleneck
Test and Repair are Non-Value-Add operations: defective products should not be produced on the first place. Unfortunately the state of the art in many processes is not there so tests and controls need to be part of the value stream. Ideally as the value stream becomes more robust some of these controls can be removed. On the mean time we need a test and repair plan (if repair is possible). A Test/ Repair loop can become a bottleneck for the whole Value Stream when Test First Pass Yield is lower than planned. A drop in FPY is normally caused by problems upstream in the Value Stream as seen in Defect generation and detection Test/ Repair loops are often absent in Value Stream Maps in spite of the potential to become the bottleneck for the total process. Download this Excel example file TestRepair.xlsm to your PC from OneDrive folder Polyhedrika You must close all open Excel files before you open this one and you should enable Macros . To simulate 1 hour operation just press F