One thing Covid-19 has unequivocally proved is that global supply chains in every industry are broken. When the pandemic began, we saw this in the empty shelves of supermarkets around the world. Today, we see this in the painfully slow vaccine rollout experienced by many countries as a result of supply issues. The fact that global supply chains are broken is not new (although current conditions seem to be even more dire than usual), but the fact that now everyone knows they are broken is. Also not new is the fact that the method that could dramatically improve the situation is getting blamed for the failure: the pull system devised by Toyota more than half a century ago, known as Just-In-Time. So it is timely indeed that Christoph Roser has launched his new book, All About Pull Production.
What is a pull system? Here’s a few words of context.
Roser’s book dives deeply into the ins and outs of “pull”, a method of matching supply with demand that is widely referenced but poorly understood. The commonly accepted academic definition of pull has been offered by Wally Hopp and Mark Spearman, who claim in their influential 2004 paper (Manufacturing and Service Operations Vol. 6, No. 2, Spring 2004, pp. 133–148) that the defining characteristic of a pull system is the presence of inventory control limits: “A pull production system is one that explicitly limits the amount of work in process that can be in the system.”