Lean Jargon – Part II, Muda, Muri, Mura

In Part I, I talked about how lean jargon in the form of Japanese words, like Kaizen, Muda and Genbutsu tend to do two things in our industrial culture: 1) workers see through the transparency of words that provide no useful purpose other than to communicate concepts rather than solve real problems and 2) managers tend to rely on words - setting the expectation that you have been told to kaizen, therefore you will kaizen. Of course, the two are irreconcilable; people solve problems, not foreign words. Part of the problem is not understanding the words in the first place.

Kaizen. It is made of two words. Kai, meaning “virtue” and “zen”, meaning “reform”.* I like to think this gives a slightly different meaning to kaizen than we are used to hearing in the U.S. In the states, people see kaizen as continuous improvement. We conduct large kaizen events where radical change is considered the best practice. In other cultures where the group benefits from individual contribution, kaizen means the improvement benefits everyone.

Muda. This word means, “wastefulness”. It applies to everything. It is everything that is non-value added. It seems Kiichiro Toyoda and Taiichi Ohno were able to classify wastefulness into seven buckets commonly seen on the shop floor, but most importantly in the context of the conditions of that time. For them, they faced a small market controlled by the government, where materials, machines, money people were a scarcity. Wastefulness was not an option. They found that inventories that were too big hurt the ability for cash to flow through the business, where it was needed, when it was needed. This is true for the American war production story during WWII. Steel, copper, people, equipment entire factories were controlled by the War Production Office. Profits were slim. Wastefulness in the form of large stockpiles of material inventories was not an option during critical war production.

Mura. This word means, “unevenness”. It applies to everything. This word embodies the concept of JIT, or Just-In-Time. If we have unevenness, we are batching. We are not making the right parts, in the right quantities, at the right time. The concept of “takt” time, is used to create a pace for people to work to. Takt is a German word, just to make it more confusing, meaning pace or beat. The takt time is the pace of customer demand. If we build to demand, we avoid unevenness in our work. We are making the most efficient use of people, materials, and machines available.

Muri. This word means, “heavy burden”. It applies to everything. This word embodies the concepts of standard work. When we observe the job, we see what is actually happening from the viewpoint of the worker. We see the potential safety issues, the ergonomic issues, the searching for tools, the walking for help, the waiting for approvals, etc. In other words, our current system, as we designed it, is a burden for our customers, the operator. All improvement is done for the operators in order to reduce the burden. The lean tools of standard work help us improve the job for operators, while improving the process for our quality, cost, delivery and safety objectives.

*translations provided via alta vista babel fish. http://www.altavista.com/