One Definition of Lean Manufacturing

During a conference call to plan the agenda for a global meeting of Lean manufacturing leaders at one of our clients, they identified their desire to establish “one definition of Lean manufacturing” at their company. This might seem like a simple thing to do, but with 10 languages spoken in their factories, a strong pre-existing foundation of Six Sigma at this company and a decision to call their Lean manufacturing program by another name, the result has been a vague understanding of the link between Lean manufacturing and their operational excellence strategy.
“The Toyota Production System is a series of activities to lower cost by improving productivity through the thorough elimination of waste.”
This is the first sentence in the first chapter from the first textbook on the Toyota Production System published by the Toyota Motor Corporation education department in 1973. It should be noted that when the Japanese say “productivity” they do often not mean only “labor productivity” but overall performance.
Since Lean manufacturing is a phrase used to describe the Toyota Production System, one definition of Lean manufacturing would be “A series of activities to lower cost by the relentless elimination of waste.” Choose your own synonyms for the words in the sentence above, as appropriate in your language, culture and business.
I want to emphasize the first four words in this definition: a series of activities. Lean manufacturing is not about theories, ideas, thoughts, philosophies, methodologies, but what you do with them. Taiichi Ohno said “Understanding means taking action” and Lean manufacturing must always be in action to reduce cost by cutting out waste.
“What about quality, delivery, safety?” you may ask. In the interest of keeping it simple, the one definition of Lean manufacturing should only talk about cost. In business, cost is how we keep score at the end of the day. Quality can and should be measured (both poor quality and good quality) as cost. There are cost elements to both on-time and late delivery. Safety has a direct link to cost. If you can not link improvements to quality, delivery and safety to improved cost in the short-term or long-term, you may need to question your measurement methods or whether it is a true improvement.
“What about muri (overburden) and mura (uneveness)?” you may ask, if you have read the recent e-mail sent out by Dr. Womack advising people to not only focus on waste, but also on variability reduction and reducing overburden. Ignore his advice. Mura leads to muri, muri leads to muda (waste). If you focus on the total and relentless reduction of waste, you will need to ask the 5 whys and get to the root cause, which will lead you back to to muri (overburden) and murd (unevenness). Keep the focus on waste. Keep the one definition of Lean manufacturing as simple as possible.
Of course if you have eliminated nearly all waste in sight and you are looking for something else to do, go ahead and tackle mura and muri. You might want to get your eyes checked first.