Pull as Kaizen

Michael Ballé’s recent Gemba Coach column drives home the importance of understanding that all of the so-called “tools of lean” are really there to drive problem solving.

A well designed kanban system is (or at least should be) built to not simply provide a pull signal, but more importantly, to continuously ask, and answer:

  • “What is supposed to be happening?” (what is the target condition?)
  • “What is actually happening” (what is the current condition?)

and give at least a hint of the problem that needs to be addressed right now when there is an issue. As a minimum, what condition must be addressed right now, and the first “Why? to be investigated.

A couple of months ago I posed a hypothetical question about a team’s effort to put in a kanban process and asked for your thoughts and comments.

The scenario I described was, with one or two trivial changes, copied directly from pages 48 and 49 of the Lean Enterprise Institute’s latest workbook, Creating a Lean Fulfillment Stream.

Although the process as described would likely work (at least for a few items), I was really surprised to see an LEI book describe a process that explicitly and deliberately breaks the “rules of kanban” that they have published elsewhere, particularly in Lean Lexicon. The LEI did not make up the rules of kanban, they have been well established for decades. Thus, I have to admit that my first response was to question the credibility of the entire book (Lean Fulfillment Stream), even though there are many things in it that are worthwhile.

Many of you correctly called out issues with the mechanics. Now, in light of this new information, I would again like to invite comment.

If a good process should be set up to continuously ask, and reveal the answers to, those two questions, where does this kanban scheme come up short?

How would those issues cause problems with the processes that Ballé is describing in his column?


One Reply to “Pull as Kaizen”

  1. Thanks to Mark and everyone who has commented on the kanban scenario, which is based on one from the workbook Building a Lean Fulfillment Stream. (Full disclosure: it’s published by my employer, the Lean Enterprise Institute.)

    I wanted to let everyone know that I’ve sent the comments to the authors who will incorporate this feedback as they make revisions for the workbook’s second printing.

    The book has nearly sold out its initial print run of 5,000 copies since the mid-May launch. Despite its success there is always room for improvement. The thinking here is that during the editing process the section on kanban was trimmed too much.

    The purpose of these pages in the workbook was simply to connect the distribution center as a pacesetter and show the need for consumption to develop the production trigger rather than a forecast. LEI has other workbooks that go deeper into kanban. However, based on feedback, we need to do some clarifying of this scene in the next edition.

    Thanks for taking the time to comment.

    Chet Marchwinski

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