Over on the Lead Edge I answer this months question from CEO Andrew Turner about Lean Implementation in different types of facilities. One is assembly intensive and one is more equipment intensive. My response was as follows:
I think this is a pretty interesting question and reflects the current status of Lean in many companies I visit. I often make the distinction that modern day Lean and the actual historical development of the Toyota Production System (TPS) are two pretty different animals. I will try and explain my opinion, provide some examples, and answer the question in the following paragraphs.
For starters if you study most of the books, training, and examples about Lean you quickly see that it is mostly assembly type of examples. That is not surprising as the assembly part of a Toyota facility is the largest section and easies to show people. Anyone can walk through and get a sense of how clean it is, how well organized, how the material moves JIT via kanban, and how work is coordinated via standardized work and PDCA problem solving routines, etc. Go to a Toyota supplier and you will see more of the same. Read most lean consultants and you will get lectured heavily about the importance of “flow”.
I agree that “flow” is certainly a necessary ingredient for the Toyota Production System to flourish but it is not the “end all be all” that it is made out to be by some parties. In strict sense 1) flow, + 2) takt time, + 3) kanban, + 4) leveling comprise the basic elements of the JIT pillar of Toyota’s improvement system. In most companies that are assembly oriented JIT and standardized work can be implemented without too much difficulty which sounds like the assembly plant mentioned in this months question.
However “lean” that may be I argue it is not sufficient enough to be real TPS in many ways – certainly not in Toyota at least. Despite all the assembly land examples we are inundated with today TPS activities under Taiichi Ohno started in an engine plant with capital intensive processes such as casting, forging, machining, a little stamping, and some assembly mixed it. It was a very diverse mixture of difficult to manufacture products (e.g. a crankshaft) and difficult processes involving complex tooling.
The actual remarkable development of historical TPS is a wonderful story with many interwoven themes in the engine, transmission, and chassis plants of Toyota during the 1950’s, 60’s 70’s and beyond. Time and this format does not allow for full appreciation of the efforts made by my former colleagues and superiors in engine manufacturing at Toyota. The story involves but is not limited to:
- Improvement of equipment uptime from a 60% level to over 90% or better
- Improvement of process capability from low levels to >1.33Cpk and often higher than >1.5Cpk or better
- Corresponding reductions in scrap and rework to minute levels today
- Improvement in cycle times and tool change over times so that minimal time is lost
- Design and development of new equipment that better fits the needs of TPS
- Safer equipment that is easier to operate
- Detection systems that stop processes at the sign of an abnormality
- Multi-handling scenarios that enable one person to handle a large number of machines
- Incredibly detailed specifications for fixture and tooling that help maintain quality
- Impressive equipment controls technology and measuring systems
- Highly involved and coordinated maintenance systems with clear roles for operators, maintenance personnel, engineers, and equipment planners
- Excellent documentation for processes (not mere standardized work) for running and operating technical machines with micron level tolerances. I once counted 12 different types of work standards particular to this type of equipment
- Tremendously skilled operators, supervisors, engineers, and managers each with an important role in improving the system
I could go on further with this list but I hope readers get the idea. Just like in real life the actual history of what occurred inside of Toyota starting in the engine shops during the 1950’s is quite different, far more relevant and interesting that what we often read about “Lean” today. Particularly for people with capital intensive situations I suggest putting down or not reading too much into textbooks built upon advocating flow and JIT topics. Instead identify what are your impediments to improvement and work on those. In particular as what are barriers to higher equipment uptime, higher process capability, safer equipment, higher capital and labor productivity without adding cost, more highly trained personnel, and you will be on the right track. I call this building better process stability and it is an essential yet often ignored element of the historical Toyota Production System.