Woodward Aircraft Engine Systems Sets Work-in-Process Levels for High-Variety, Low-Volume Products

We developed a method for setting the work-in-process (WIP) levels for products manufactured in a plant that operates in a high-variety, low-volume environment. We implemented the method on a spreadsheet using Visual Basic macros and used an iterative algorithm to find the WIP levels needed to meet required throughputs for different products. We applied the method at Woodward Aircraft Engine Systems, Rockford, Illinois, which produces high-precision components with long setup times. Using the spreadsheet, plant supervisors can quickly analyze several alternate scenarios. They have reduced WIP levels in some cells to one third of their original values.