The meaning of this famous quote, attributed to Taiichi Ohno, becomes much more clear in the context of “Chasing the Rabbit” and previous published research by Steven Spear.
Spear’s research goes beyond Toyota’s process and delves into a more general question about how any organization playing in an otherwise level field can continuously out perform similar organizations in similar circumstances. This makes Toyota is a subset or an instance of a very fundamental principle, rather than a special, complex, unique case.
I think that is important. Some critics say Spear is making a soft version of the TPS. I think quite the opposite. He is explaining why it works.
And why it works comes right back to Ohno’s quote.
To better understand Ohno’s quote, let’s compare Ohno’s context with Spear’s.
All of us have been taught Ohno’s three elements of standard work:
- Takt time
- Work sequence
- Standard inventory
In “Decoding the DNA of the Toyota Production System” (a summary of his PhD dissertation), Spear describes the first rule-in-use he observed:
All activities are highly specified in terms of content, sequence, timing and outcome.
Further, Spear’s research concluded that the process steps themselves include frequent, nearly continuous, built-in checks that are designed to call attention to any departure from the specification. It is those built in checks which, on an assembly line, trigger an andon call and start the escalation process.
It is the escalation process which, in turn, results in problem solving and improvement.
It is any departure from the standard which calls the standard itself into question and results in investigation to understand more about the process.
The elements of takt, sequence and standard inventory define not only standard work, but they define elements of the built-in checks.
Takt time is the standard. Cycle time is the actual.
Actual cycle time is compared to the takt every time the process is carried out. If it takes longer than expected – problem, andon, escalation, problem solving.
The defined work sequence is the standard. It is (or should be) checked against the actual work sequence every time it is carried out. If something knocks the worker off the standard sequence – problem, andon, escalation, problem solving.
The standard inventory is the minimum amount of inventory required for the process to be successful at takt. Just as the work cycle is timed against the takt time, actual inventory can be compared with the standard. Too little? The process gets halted. That is a problem. Andon, escalation, problem solving. How do you check for too much inventory? Inside a process, specified inventory locations (5S, folks!). Inventory out of place? That is a problem. Andon, escalation, problem solving.
In regular takt-based work, these things in combination are a very effective set of cross checks of actual vs. specified work. BUT these are only tools that set up the system for kaizen.
It is the problem solving – the seeking to understand why the exception occurred that is true kaizen. This should must happen rapidly and every day. Not just during special “events,” every day.
It is part of the work, just like putting on protective equipment, just like maintaining the machines, just like cleaning up. Only this part of the work actually improves the operation.
So – without first specifying what is supposed to happen, there is no way to determine if what actually happened is routine or cause for investigation, learning and improvement. Then the exceptions become the routine because there is no expectation of otherwise. Look up the term “normalizing of deviance” and get an idea what the ultimate consequences can be.
That is why the first step in improving a process is often to attack ambiguity itself. This is especially true in administrative processes, and it is critical at the points where one process step turns over work to another.
If a defect-free outcome has not been specified, people are left with the leadership cop-out of “do the best you can” and that results in continuous erosion of morale, quality, delivery, cost. It is anti-kaizen. It is what is very much like kaizan – faking it.