What is the science in Lean? | Jeffrey Liker | The Leadership Network

Michel Baudin‘s comments: Is there science to Lean, TPS, or, more generally, manufacturing? There is definitely technology and there is management. Technology is about getting inanimate objects to do what we want them to; management, about working with people. Science is not about getting anything done but about understanding how nature works.

The difference between science and technology was driven home to me by a joke I heard about a scientist, a high-level engineer, and a basic engineer each designing a bridge, with the following outcomes:

1. The scientist’s bridge collapses but he explains why.
2. The high-level engineer’s bridge collages and he doesn’t know why.
3. The basic engineer’s bridge holds but he doesn’t know why.

This is, in fact, not just a joke, as the collapse of the Tacoma Narrows Bridge in 1940, a failure of technology, is now viewed as having enhanced our scientific understanding of the effect of wind on structures.

It’s not a trivial distinction. Technology has been based on science for about 300 years but it’s a different pursuit. When you design, operate or improve a factory, your goal is to make it a viable business, not to further understanding. You do apply available prior knowledge and you enhance it but it’s a by-product of your efforts, not their primary purpose.

The same is true of management. It’s about getting things done with people. “Scientific Management” was not a science but a label used by Frederick Taylor to enhance the credibility of his methods. The point of management is not to further our understanding of human nature but apply what we know about it to plan, organize, lead and control the activities of people in alignment with the goals of the organization.

Science, as pursued for the past 2,500 years, is not easy, particularly when it is about people and societies.  Many philosophers have thought hard about how to do it, from Aristotle to Karl Popper and E.T. Jaynes. They would turn over in their graves at the thought of the scientific method being reduced to PDCA.

Pitch PDCA to PhDs and they will throw you out. “Plan-Do-Check-Act,” on its face, sounds barely more specific than “Be careful.” Yet I know it to be useful to other audiences.  The Legotractors game involves three 20-min production rounds separated by 50 minutes for the teams to think through and implement improvements in assembly.

Each production run is a check on the last design. Within these 50 minutes, each team is expected to act by reflecting on what worked and didn’t, plan improvements to the assembly line, and implement these improvements (do). Even though we never said it explicitly, the whole game could be viewed as an exercise cycling through PDCA.

What was fascinating to watch is the response of different players to this challenge. Some groups coalesced into teams that were comfortable with the disciplined approach; in others, forceful individuals attempted to push through solutions they thought were obvious, with varying degrees of success; in others yet, individuals immediately went off to make changes on the production line rather than participate in the team’s discussions.

What I saw as a facilitator, however, was that PDCA was not so obvious to all the players. They come from all layers of the organization and, as a rule, play other roles in the game than in real life. Most of the players who struggle are in one of the following two categories:

• Employees who have been discouraged from doing anything other than follow orders. In private life, they may be club presidents but, at work, their ideas at work were neither solicited nor appreciated.
• Managers and engineers steeped in a “ready-shoot-aim” culture that values nothing other than doing. Planning is viewed as a waste of time and, since all they do must be a great success, they are wary of checking outcomes.

Needless to say, the consequences of these choices are visible in the outcome of the game. The more organized teams outperform the others and this is often a key takeaway for the players.

While PDCA is trivial and obvious for some, it is worth emphasizing with others. It is a rational framework for improving processes but it doesn’t add up to the scientific method.