PFA
(Production Flow Analysis)
At The Ohio State University, I received federal funding to develop the methods and software for implementing JobshopLean in custom forge shops that supply forgings to the DOD (Department of Defense) and DLA (Defense Logistics Agency). These custom forge shops are job shops that produce small lot sizes of a variety of forgings that are needed to maintain legacy weapon systems. So they had little in common with an OEM like Toyota! My sponsor was intrigued by the idea that Lean would be implemented differently in job shops, compared to how it is implemented at/by Toyota in their assembly factories.
Luckily, at that time, I was doing research on Group Technology and Cellular Manufacturing. Luckily (again!), just around that time I had learned Value Stream Mapping (VSM). VSM is a simple and effective method to plan the implementation of Lean in high-volume low-mix assembly facilities and other repetitive work environments. I noted the following key parallels between Lean and JobshopLean:
|
LEAN |
JOBSHOPLEAN |
|
Assembly Line |
Manufacturing Cell (“Mini-Jobshop”) |
|
Single Product (Family of product variants) |
Part Family (Large number of parts that a cell can produce) |
|
Make-To-Stock based on kanban signals |
Make-To-Order based on due dates |
|
Pull Scheduling |
Jobshop Scheduling |
Based on the analogy between Value Stream and Part Family, it was a no-brainer to use the method of Production Flow Analysis (PFA) to form the part families and implement a manufacturing cell to produce each part family. Also, the efforts made to overcome the constraints and obstacles to implement each cell became the Continuous Improvement strategy for implementing JobshopLean one cell at a time.
PFAST
(Production Flow Analysis and Simplification Toolkit)
PFAST (Production Flow Analysis and Simplification Toolkit) is the software package used to implement PFA hierarchically at each of the four levels of a typical factory:
Factory
↓
Shop
↓
Cell
↓
Machine
Additional Reading
Please click here to access the presentation Reduction and Simplification of Material Flows in a Factory – The Essential Foundation of JobshopLean.