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.