The term scientific thinking has been used with increasing frequency in the Lean management community over the past decade. The idea is not new. There is little doubt as to its importance in continuous improvement, good management and good decision-making. The introduction of the so-called Toyota kata approach to improving and coaching the PDCA cycle has popularized the notion of scientific thinking and efforts to practice it. However sometimes I can’t wonder if the community, or parts of it, haven’t glommed onto this “new” idea in a similar ways as we have done with many other buzzwords in the past. Namely, adhering fondly to a favored method at the cost of understanding its limits. Specifically, I am encountering more cases where people are touting scientific thinking when what the situation calls for is engineering.
Scientific thinking is a good thing. Any time we use our minds to critically examine a situation, practice logical reasoning and approach our presumed knowledge and assumptions with an attitude of skepticism, we improve the quality of our thinking. This rigor gives us a better chance at making discoveries that lead to improvement. Scientific thinking aims to reduce uncertainty by disproving hypotheses. This relies on data gathered from observation and experimentation. By their nature, such experiments are low-yield propositions. Most scientific experiments fail. The aim of science is to create knew knowledge. It is to turn the unknown into the known. This is all good, but not always what is needed when we are working to build, maintain or improve a modern management operating systems.
Engineering on the other hand, is the application of scientific principles to design and build things that do what we want them to do. This includes machines, lifeforms, structures, processes, systems and so forth. Engineering deals largely in the known and proven. Engineering is not about creating new knowledge, it is about inventing novel solutions to a problem or making improvements to existing solutions. Engineering works in the realm of applying well-understood principles to new or extended situations. Compared to scientific experiments, engineering efforts are higher yield, and often higher-states with failures being more expensive. For example, through scientific experiments we can test new materials for bridge-building in a lab and survive many small failures. One failed experiment in engineering a working bridge can be too expensive to even contemplate.
Scientific thinking which requires reproducibility, peer review and rigor with both method and data. The test of engineering is “Do we know that works?” and “Did it work in this application?” If an engineering solution reduces effort, difficulty, danger or even the current impossibility of a task, we call this a success. Understanding the underlying scientific theory is far less important to us as long as the mechanisms work consistently. It is the job of the engineer to come equipped with the technical knowledge and tools in such a way as to be able to recombine these in novel ways fit to the situation. This is why we rely on engineers to design and build things. Engineers in turn rely on scientists to do the fundamental research to give them better tools, methods, materials, theories and so forth.
The premise of Toyota kata is that there is threshold of knowledge that we must experiment our way through via scientific thinking. Should we always accept that this is so? Even if these threshold or gaps of knowledge exist for us personally, must we face them as scientists? When is it appropriate to call in the engineers who already know how to build bridges, figurative or physical, to span these gaps? In truth it is not either-or, and the current popularity swing towards scientific thinking may simply be a reaction to the decades of engineering-driven Lean. But to this I would pose the question of whether we scientifically understand the reasons that previous approach didn’t always work, and whether the solution is always kata.
One of the goals of Lean management is to enrich the lives of people. This means developing people. Among other things, this means making people better thinkers. Scientific thinking is one important upgrade for most of us. But is the goal of Lean to develop scientists? What if this comes at the expense of building systems that are less effective, more expensive and take longer to complete? When I see Lean coaches who teach kata and watch their teams develop something better but still far from textbook 101, it makes me wonder why we are doing the equivalent of high school science experiments in an aerospace workplace. It seems that scientific experimentation should be the approach only when we arrive at the very edge of available knowledge, after we have studied and adapted the state-of-the art methods for ourselves. This requires engineering. What I question is the “kata first” approach that skips basic benchmarking, study of the tools, research on application in similar environments, and mistakes unstudied ignorance for a true “threshold of knowledge.”
Some argue that it is better to let reinvent the wheel so that they experience the joy of finding the solution, even it if is already known by many. This can build buy-in and a sense of ownership of that solution. It also teaches scientific thinking. One problem with is that people arrive at a half-way solution, a flawed version of an established Lean method, and defend it rather than continue to evolve it to and beyond the state of the art. If we are developing people through thinking and practice, why not as engineers? Start by setting down the immutable scientific principles, such as flow and pull in Lean terms, and encourage people to invent ways to apply these principles and Lean tools to their situation. Scientific thinking can still be learned in the process of finding new applications rather than new knowledge.
In the Toyota management language, there is much talk about doing things scientifically. However they do not talk about turning their people into scientists or even scientific thinkers. The aim of all of that PDCA is to deliver better products and services to the customer, to contribute to society and thereby to make profit that sustains the business. In their manufacturing operations, scientific thinking exists to serve what they call seisan gijutsu or production engineering. Perhaps this point was missed by Western researchers because the term gijutsu can, depending on context, mean skill, engineering, technique, skillfulness, technology or art. In the plants, well-polished gijutsu at all levels is what allows Toyota to build reliable cars on-time at a low cost. Their practice of kata aims to develop gijutsu in people, processes and products.
Can we have too much scientific thinking? Sometimes I wonder. But as long as we are clear about what state of the art we are attempting to advance through our scientific thinking, we can always use more.