Apr 7 2012
My previous post on this subject listed some requirements on metrics to be useful on the shop floor. Here, we take it one level further, first by establishing that shop floor metrics should be in the language of things rather than the language of money, and then by using the requirements to evaluate examples of quality metrics. In later posts, I will do the same for other dimensions of manufacturing performance.
Mar 31 2012
Ever since childhood, we all want to know what grades we get on our report cards, and what these grades mean in terms of how well we are doing. We want to be evaluated based on parameters we understand and we can affect by our efforts.
A key issue in manufacturing is consistency as we go from a shop to a department to an entire plant and to the company as a whole. We don’t want to use parameters in terms of which excellent local performance can aggregate to poor global performance. Once performance measures are selected, the next challenge is to use them as a basis for management decisions that are in the best interest of the company while being fair and nonthreatening to employees. In particular, actions taken to improve one aspect of performance must not degrade another. In addition to these issues, in a lean environment, we need to consider the impact of improvement projects, before and after they are carried out.
Mar 28 2012
Let us return to the slogan “Muri, Muda, Mura,” and see if there is something new to say about Muda, the one that is discussed to death. Just in this blog, it is already the subject of the following four posts:
What more is there?
In daily life, a “waste of time” is an activity that you can stop doing without any adverse effect. It is no different in manufacturing: an activity is “muda,” (waste) if you can stop doing it without lowering your performance in any way; a device is “muda” if you can dispose of it and nothing gets worse. Stopping overproduction, for example, won’t hurt your quality, productivity, delivery, safety, or morale. It is a simple and actionable idea: if you look closely enough at what you are doing on a manufacturing shop floor, you can tell in those terms what is necessary from what isn’t.
Many authors, however, feel compelled to make it more complex, more abstract, and less actionable. Following are a few examples of attempts to define waste — as a translation of Muda — that I think are generating more heat than light:
- Anything that does not physically change the product. Shipping does not physically change the product. Yet, unless we can manufacture at each customer site from materials extracted from the ground right there, delivery is impossible without shipping. Packaging prevents the physical form of the product from being changed during shipment, which would make it defective. Calling packaging or shipping “waste” when both are obviously necessary to order fulfillment is. at best, confusing.
- Anything that the customer is not willing to pay for. Manufacturing involves many tasks that customers need not be aware of, let alone express a willingness to pay for. You don’t ask customers whether they are willing to pay for revision control on engineering changes. If, however, you stopped doing revision controls, the consequences on quality would be dire. Therefore it is not waste.
- Not doing things right at the first time. This brands as waste any activity that requires experimentation or iteration.
Ohno’s list of seven types of waste is the subject of countless PowerPoint presentations, most of which I find not only tedious, but actually misleading. The most common misconception is that the seven list entries are mutually exclusive categories. The point of Ohno’s list is not to categorize the waste but to help you recognize it when you see it. It guides your observations when you walk the shop floor. The items in Ohno’s lists are symptoms rather than categories. You can observe both overproduction and excess inventory, but they are obviously not independent phenomena.
Ohno’s list has seven elements because it is Japanese, and seven is a lucky number in that culture. Other Japanese lists of seven elements include the old 7 tools of QC and the new 7 tools of QC. Akira Kurozawa’s movie is the Seven Samurai, and the samurais’ way of the warrior specifies seven virtues… It may be related to Buddhism having seven factors of enlightenment. Although it also has lists of seven, like the deadly sins or T. E. Lawrence‘s biblical Pillars of Wisdom, the Judeo-Christian world prefers lists of 10, like the 10 commandments or the US bill of rights.
I think this is one cultural reason so many want to expand Ohno’s list. All sorts of additional entries have been proposed, including skills, unused competence, unused space, government, meetings, unemployment, complexity, poor communication,… It is not clear to me that such additional entries belong in parallel with Ohno’s seven or help you identify waste on a manufacturing shop floor. As Rogério Bañolas pointed out, however, Ohno’s list is not necessarily on-target in activities other than manufacturing.
There are also practical considerations about the length of lists. Seven entries is about as many as people can remember. Lists of ten are too long: few Americans can tell you what the 8th amendment to the US constitution says, and only the most devout Jews and Christians can recite all the ten commandments. Lists of 14 even worse, like Woodrow Wilson’s or Deming’s 14 points, to which I would add Jeffrey Liker’s 14 principles of Lean in The Toyota Way.
Even a list of seven is a challenge to remember without the help of a mnemonic like TIMWOOD, which stands for “Transportation, Inventory, Motion, Waiting, Overproduction, Overprocessing, and Defects.” It is undeniably useful, but we have to be careful in not being misled by it in at least the following two ways:
The qualifiers make the explanations a bit more complicated. Without them, however, the list may look more elegant but it does not make sense.
Once you have identified waste, all you have to do is get rid of it, right? If only it were that simple! Sometimes it is, but rarely. Most of the time, getting rid of waste involves both technical and managerial changes, and going after each observed item of waste one by one would be ineffective. The list can be very long, and its entries interrelated. That is why you organize Lean implementation in projects to redesign production lines, increase equipment flexibility, or change policies in production control, maintenance, quality, human resources, etc. The waste that is observed is the gold in the mine; the projects, the means of extracting it.
Technically, getting rid of the waste is always feasible, because, by definition, waste is unnecessary. There is, however, a difference between knowing that something is feasible and having done it. That is where Lean implementation skills come into play. Learning of the existence of opportunities is an important first step, but only the first step.
Mar 27 2012
Via Scoop.it – lean manufacturing
The plant is described as a “Toyota-style, lean, manufacturing line.” Current GE CEO Jeffrey Immelt does not once mention his predecessor’s flagship initiative, Six Sigma.
Mar 13 2012
“Muri, Muda, Mura” is often mentioned in the Japanese manufacturing literature as a trio of evils to avoid. Of the three, Muda gets the most attention. Usually translated as waste, it designates everything we do in a factory that is unnecessary. For a change, let us focus on Muri.
Muri, in everyday Japanese, means impossible, with the nuance of unreasonable or unsustainable. A person working exceptionally hard is said to be doing Muri. Other words are used to say that something would violate the laws of physics, or that it is socially improper or inopportune. When there is Muri in your process, it means that you are asking people to work too hard, which results in defects, burnout, repetitive stress injuries, or even accidents. Conversely, removing Muri means making your process humanly sustainable, so that is can be executed as well at the end of a shift as at the beginning, by a 50-year-old or a 20-year-old, a man or a woman, 5 or 7 feet tall.
It cannot be repeated often enough that Lean is not about making people work harder but instead, in the tradition of Frank and Lillian Gilbreth, in making the work easier to do. When you observe a truly Lean plant, you do not see operators hurrying. Instead, you see them working steadily, at a sustainable pace, at jobs that are carefully choreographed for effectiveness and efficiency. A key example of Muri elimination is the raku-raku seat shown above. It is a device introduced at Toyota in the 1990s and now adopted by many car makers to remove the need for operators to crawl into car bodies in order perform assembly tasks inside.
There are many tools to remove Muri. You can easily notice that an operator is overburdened by direct observation in the shop. A more systematic approach is to use Toyota’s TVAL to rate jobs based on the weight operators have to carry and how long they have to carry it. TVAL establishes an equivalence between combinations, so that, for example, carrying 4 lbs for 200 seconds is equivalent in terms of fatigue impact to carrying 10 lbs for 4 seconds. You then focus on the jobs with highest TVAL ratings and improve these jobs to reduce it.
Once you know which job to focus on, you record it on video and review it with the operator to identify ways to make it easier or to offload parts of it to others with lighter burdens. If the job involves interactions between operators and machines, you analyze with with a work combination chart to improve task sequencing and identify tasks within the job that need better tooling or a better work station layout.
Apr 10 2012
China Is Ready for Lean Projects, like the Rest of the World
Via Scoop.it – lean manufacturing
This article asserts the opposite. According to it, “Lean principles are based on Western ideas and methods.” I never thought Japan was part of the West. And Lean is supposed to be incompatible with “the teachings of Confucius,” that are at least as influential in Japan as in China. According to the author, China has been confucianist for 3,000 years, which puts it at 1,000 BCE. It is interesting, considering that Confucius wasn’t born for another 500 years. It is like making Steve Jobs a contemporary of da Vinci.
It might have occurred to the author that there might be more immediate reasons for her problems implementing Lean in the Pearl River Delta. For one, a labor structure that is similar to that of the maquiladoras of the US-Mexico border: girls from the hinterland coming to work in factories for a year or two. For another, in management, the lingering influence of Maoism.
All the factories in the world draw their work forces from societies with their own cultural idiosyncrasies. This is equally true in the US, France, Russia, or China. However, once on the shop floor, dealing with machines and production lines, the national culture is little more than background noise. You have to pay attention to the local etiquette, but that is not a show stopper.
Via www.scmr.com
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By Michel Baudin • Press clippings • 5 • Tags: Lean, Management