John Bicheno, Course Director at the MSc in Lean Enterprise at University of Buckingham and the author of The Lean Toolbox, guides LMJ through the evolution of lean tools.

In a January 2013 Linkedin blog on lean healthcare the group discussed an appropriate response to the US high school shootings in Connecticut. One blogger, joined by several others, suggested: “Bring in the Toyota guys with an A3.”


Wow! What next for lean tools? Afghanistan? Debt crisis? Global warming? I am a lean enthusiast, but I seem to have missed the potential.

In this article we will look at the evolution of Lean tools and related concepts. Of course, that is not the same as looking at the evolution of Lean itself.


Keep in mind that learning tools is not, by itself , good enough. As with weapons, or carpentry, one needs the skill to use the tool. And the skill to use the tool comes with practice, over and over, until it becomes habit. This is one of the great learnings from TWI (training within industry). It was recognised in 1942 when TWI began, but much lean, six sigma, systems “education” has focused too much on the tool and forgotten the skill and practice.


It takes genius, like Ohno, to see a new paradigm into which current and new concepts can be unified. Like building a cathedral, the vision is clear but tools are used in the construction, and new and better tools and methods are found along the way. Whilst “toolheads” are often rightly criticised, tools are essential. Deming said that principles should remain the same, but methods for getting there should constantly change.

Most concepts follow an S curve evolution: slow early growth, take off, rapid growth, slowing, plateau or decline. Other S curves take over. There are smaller S curves within larger ones. That is probably true for lean tools, and lean itself. An S curve may last days or decades. During the take-off stage there is often huge enthusiasm when the concept is seen to apply widely, before a more considered view sets in.

In the initial period of enthusiasm caution is called for. Michael Baudin likes the concept of “winter fan, summer heater” to emphasise inappropriate application. A3 for gun control? And John Seddon advises one to always ask, “Who invented the tool, for what purpose, and do we have a similar situation?”

In Table 1 the evolution of a number of central lean tools is given.  There is a common thread between the initial approach and the second tranche. The common thread is that of participation in learning the application of the tool in context. In other words, learning the skill as well as the tool.

Some macro tools help to see several other concepts in context. An example is Little’s Law (relating entities such as units of inventory, money, customers, with the rate of flow through a system and the average time in the system). Another is Kingman’s equation that gives the interrelationship of key variables in lead-time (arrival variation, process variation, and utilisation. Utilisation is further decomposed into load and capacity, with load having components of true load and rework, and capacity made up of base capacity minus waste). Both of these date back to the 1950s.

Then there are major concepts related to lean that also follow their own S curves. Taking a rather cynical view, Kirkor Bozdogan of MIT’s Engineering Systems Division calls all of these, including lean, “marketing brands, developed by consultants for marketing purposes.” They evolve, according to Bozdogan, from successful projects that then lead into consultancy, naming the concept to distinguish it, diluting it into ever-broader classes. From this dissertations and books get written, and even later magazine articles appear bemoaning a failure to deliver expected results.


Begin with Table 2 – an imperfect view, but an impression.

From the Table and from Bozdogan’s 2010 study, we may make the following tentative conclusions:

  • Lean manufacturing is stabilising. But there is growth in lean service, lean health, lean design, lean accounting, etc.
  • Lean six sigma has been the big growth area over the past few years. Passed its peak?
  • Six sigma is declining.
  • Agile operations are almost dead, but agile software and project management are big growth areas.
  • Systems thinking has had a boost.
  • TPM is on slow decline.
  • TOC has lost ground significantly.

Here follow some observations:

Six sigma. Evolved out of Motorola. Started the clever ‘black belt’ label, and got a significant boost from Jack Welsh at GE. In the late 1990s separate lean and six sigma functions were seen. One analogy is of six sigma being a surgeon, targeting a highly specific illness. Lean, so the analogy goes, is the public health engineer targeting prevention in the community but enjoying less status.

What happened? At least for some, a huge training effort leading to an oversupply of black belts. Six sigma training began to be offered by poorly qualified opportunists, leading to brand dilution. But low hanging fruit was removed, and in due course the oversupply became apparent. The elitism of the black belt problem solvers began to be seen as undesirable. This led to…

Lean six sigma. Is this an oxymoron? The health analogy is that both are needed, but surgeons and engineers need to recognise the unique strength of the other and to work together. Day by day, public health prevention needs to be worked at, at detail level. Occasionally the surgeon is needed for intervention or consultation. Some knowledge about the others’ skills is certainly desirable. But questions remain: What levels of continuous improvement ability are required? Does the label of ‘lean six sigma black belt’ create elitism and division? Are the previous six sigma opportunists back under a new guise? PDSA or DMAIC? Variation or mistakes?

Systems thinking. Systems is a concept older than JIT/lean. Ohno never thought himself a systems thinker, but his systems orientation has been recognised. Likewise Deming. Systems thinking comes in many forms, like the US versions of system dynamics and Ackoff, and the UK versions of soft systems and viable system model. Systems purists often say that lean is not proper systems. So what? But some central systems ideas should be part of lean, and are growing:

  • “The systems approach seeks not to be reductionist,” says Peter Checkland. “Seeks” because keeping the big picture in mind is challenging. As was said, “if you take a dog apart to see how it works, the first thing you get is a non-working dog.”
  • System boundary. Should the machine be considered, or the cell, or the value stream, or the supply chain? This applies to people, operations, and measures.
  • “The systems approach begins when you first see the world through the eyes of another,” said West Churchman. Look at implementation from the perspective of the customer, the manager, the worker, the supplier, the union, the shareholder…

Agile. The agile manufacturing concept has all but disappeared in publications, but has resurfaced in software development where it is joined by lean and “SCRUM”.


Of course, one would expect lean and related concepts to evolve. All have S curves. The question is which tools and concepts will prove the most robust? For now, I doubt lean’s ability to address gun control.