In Part 1, we asked whether it was true that lean was “all about the people” and saw that lean was at least as much about flow, batch size reduction, and the various lean methods that enable this. What are the other two main factors of lean, and how do they compare in importance?
Visibility. Because we are talking about humans, whose most information-rich sense is vision, we refer to abnormality management as visualization or visual management or visibility in the English lean vernacular. This naming confuses the method with the aim. We are presenting abnormalities visually so that we can respond to and manage them better. A more accurate term would be “perceptibility” if we wanted to encompass vibration sensing, acoustic error sensing, and other automated abnormality management methods. Whether they flow fast and smooth or in turbulent batches, systems change due to external factors, human intervention or entropy. Lean does not work without the ability to monitor system and be aware of the performance of the system. Humans invented various lean methods, from 5S to huddle boards to hour-by-hour charts to andons to kanban systems to mistake-proofing to standardized work to kamishibai to jidoka, for this purpose.
We could say that abnormality management is a form of batch size reduction applied to the detection and correction of problems. We make things visible so that we can see the very first sign of deviation from standards, deterioration of equipment or other signs of trouble, rather than waiting until the problem becomes too big to ignore.
The detection of abnormalities and problems often requires human observers, but not always. Humans have been clever enough to set up automatic error-detection-and-response systems even a century ago, as evidenced by the very earliest jidoka mechanism in the autonomous loom. Well-trained AI will increasingly detect and manage abnormalities in our systems.
We could equally say, “lean is all about visibility.”
Humanity. Last but not least, there is the human factor. It is people who do the work, and it is people for whom we do the work. When we say that flow aims to transform inputs into higher value outputs using less time, this relies human judgement and opinion to say what has higher value. Lean systems do not define value, people do.
The lean approach to engaging people in problem solving, improvement and innovation is team-based and evidence-driven. It places emphasis on gemba go see over expertise-based conjecture. It uses low-cost creative approaches before spending money on sophisticated off-the-shelf technological solutions. These things recognize the social character of humanity, that large numbers of human brains find better solutions than a few elite or highly-specialized brains working alone.
Humans also have the capacity to learn, teach, remember and record things. The act of engaging people in both doing their work and in finding ways to make it easier, safer, better and faster develops more capable people who are more satisfied at work. As a result, speed, quality and cost of the system improves, we set better standards, and we detect abnormalities more readily.
Where does all of this leave the question about whether “lean is all about people”?
Is the people factor more important than flow to the success of lean? We can have the most highly engaged people but unless we grasp the practical science of batch size reduction, quality and speed will forever lag. Is the people factor more important than problem exposure and detection? Even highly engaged people working within a process with perfectly optimized batch sizes, queues and flows cannot guard against the inevitable degradation of that system unless they have great monitoring methods. Clearly it cannot be “all about” any one of these things. Lean is a three-legged stool, and people are one of its indispensable legs.