Every part every interval (EPEI) is my favorite lean metric for high mix/low volume (HMLV) value streams, and it’s probably the least known. It’s especially helpful when changeovers are a significant portion of capacity, as frequently is the case with machine-oriented operations.

I want to share how I’ve used EPEI in lean transformations rather than establish its usefulness or provide the math. These are snippets of how I’ve used and adapted EPEI to address the challenges of high mix/low volume value streams. The information that follows should get you thinking, but it’s not a comprehensive explanation of the metric.

Favorite nonmath definition of EPEI. EPEI is the time it takes to produce every member of a product family, including the changeovers between products.

 …