I have recently had to reply to a thread about history of the (software/IT) Kanban method on LinkedIn, which stated that the (software and IT) Kanban method originated from Taiichi Ohno’s Toyota Production System and went into the direction I didn’t find useful. I hope my remarks were useful to the original poster as well as several others and I want to repost them here for the ease of future reference as well as, possibly, for others’ benefit.
The main point of my remarks was that the Kanban method as we know it today has many other influencers and origins besides Ohno and TPS. Two such influencers were of course W. Edwards Deming and Eliyahu Goldratt. Demings 14 Points and the System of Profound Knowledge guide Kanban change agents worldwide.
Goldratt’s influence manifested in what is now considered the first software Kanban implementation dating back to 2004. It was a successful attempt to apply Goldratt’s Theory of Constraints, particularly its Five Focusing Steps part in the software world after modeling an existing process with a drum-buffer-rope system. The details of this implementation can be found in a certain blue book with a cartoon on the cover and I assume, if you’re interested in the subject of this post, you have already read that book. It is important to note that there was little relationship between Goldratt’s Theory of Constraints as it applied in that particular case and the TPS. As noted in the foreword to the above-mentioned book, improvements within TPS had little to do with bottlenecks, the main concern of the Theory of Constraints, and a lot to do with reducing batch sizes.
The start of the 2006-07 Kanban implementation that followed was influenced in large part by Donald Reinertsen, who had researched product development flow for many years before that. Among Reinertsen’s insights were that variability has economic value in knowledge work and that kanban systems were better suited to it than drum-buffer-rope. Such realizations had to be preceeded by a deep inquiry into the nature of knowledge work, which was carried out in the middle of the last century by Peter Drucker. David Anderson, in his book “Lessons in Agile Management”, actually credits Drucker as one of his key influencers.
The year 2007 also stands out in this story as the year of discovery of the Kanban method as opposed to a kanban system. Establishing the distinction between the two marked a significant departure from the TPS and other Lean manufacturing systems.
Post-2007, as the popularity of the Kanban method grew, questions about its applicability in a variety of contexts arose. Developed by Dave Snowden for many years prior to that, independently and for unrelated purposes, the Cynefin framework turned out to be instrumental in answering such questions.
The fourth element of Deming’s System of Profound Knowledge is psychology. Deming realized that, since systems of work we’re trying to improve involve human beings, understanding how humans behave and make decisions had to be an important part of the improvement; however, he really left it to future generations to figure out. On the boundary of psychology and economics a whole new field evolved in the 2nd half of the last century, known as behavioural economics. Many researches worked in this field, but one that stands out is its pioneer Daniel Kahneman, who not only made key discoveries in this field but also documented them in a popular form. Psychology and behavioural economics have become an important part of the practice of the Kanban method today.
Thus the “watershed” of the Kanban method circa 2013 has many “tributaries” of which the TPS is only one. Those other sources should be studied by those how want to apply the Kanban method effectively as change agents.