Figure 1 This shows a job packet and bin sitting at Cell K. The U/K card shows where the parts came from (Cell U), and the K/V card shows where the job is going (Cell V). Pull production sounds great in theory, and it’s not unheard of in sheet metal fabrication. Demand from customers, both internal and external, “pulls” products downstream and, ultimately, to the customer’s receiving dock. This can work spectacularly well for specific products. In fact, it’s not unusual to visit a fabricator and see a multiprocess cell dedicated to one major customer. Returnable containers arrive from the customer, which spurs the cell into action. If the containers aren’t there, the demand isn’t there, so the cell doesn’t produce that product but instead shifts to another (usually similar) product. It’s a simple adaptation of kanban replenishment concepts long used in lean manufacturing. But then you look at the rest of the fabrication shop floor. It’s organized by process, like a typical job shop. You see large work-in-process buffers between processes. Then there’s the typical chaos: A big customer calls and needs a part immediately, and an expediter springs into action. A custom fabricator ...