Henning Blunck
June 8, 2020
To Pull or not to Pull: What is the Question?
If you ever found yourself arguing that Pull was somehow that same as make-to-order, I strongly recommend this paper by the authors of Factory Physics.
Wallace J. Hopp, Mark L. Spearman, (2004): “To Pull or Not to Pull: What Is the Question?" In: Manufacturing & Service Operations Management 6(2):133-148 (available online).
In it, the authors (successfully in mind mind) argue that the true discerning trait of a PULL system is the fixed upper bound on the total inventory in the system (as implemented e.g. by the total number of Kanban Cards).
As for the often cited equivalence between PULL and make-to-order, the authors give the example of a supermarket: Clearly, any product you would find on a shelf in a supermarket was not made to your customer order (rather it was made to stock or made to forecast). On the other hand side, building a cruise ship ship clearly is an example of “make-to-order” production, yet it will usually not exhibit many other traits of PULL production.