Lean manufacturing

The pursuit of concurrent improvement in all dimensions of manufacturing performance through projects involving both the production floor and support services.

Mar 2 2012

The origins of Lean – as viewed in France’s L’usine Nouvelle

The French magazine L’Usine Nouvelle is similar to Industry Week in the US and has a special place in my heart as the first organization ever to pay me for my writings. I wrote an article for them on quality in Japan in February,1981, and they sent me a check.

Last week, the current editor in chief, Thibaut de Jaegher, wrote the editorial translated below:

At the origins of lean manufacturing

Published February 25th, 2012 at 11 55 | L’Usine Nouvelle No. 3273

Everyone seeks their own production system. The Renault-Nissan Alliance has its production way, and so does Michelin. Alstom has developed its Apsys,  SEB its Operational Performance Plan …

Since the publication of the book “The Machine That Changed the World” in 1990, manufacturers worldwide have embarked on a frantic quest to eliminate waste, improve quality, and increase productivity.

Because this book coined the phrase lean manufacturing, we also think that Toyota is the instigator of these organizational methods. It is not the case.

Since industry has been industry, manufacturing engineers have sought to continuously improve their manufacturing methods. It only became a Japanese specialty after World War II. Before, the search for more efficient production systems and a scientific organization of labor was rather the prerogative of the Americans.

The first production standards have emerged during the Civil War, to facilitate the repair of guns on the battlefield. The American system of manufacturing (ASM) was used to accelerate the manufacture of guns and their maintenance during operations.As in the Toyota production system, this organization was based on two pillars: standardization and mechanization. And one might think that all sites of Springfield (the manufacturer of rifles) turned in just in time because of the war.

The ASM was probably one of the competitive advantages that allowed the “Yankees” to win.

I posted the following comment on 2/26:
This is another article that denies the contributions of the developers of Toyota’s system. To say that they did not invent anything and that everything they have done is just a rehash of American industrial engineering is like saying that Einstein’s theories are that a copy of Newton, Maxwell, Lorenz, etc..

As in all disciplines, advances in production techniques are based on previous achievements. The American System of Manufacture is a set of techniques aimed at the manufacture of interchangeable parts. It dates from the 19th century. It included among other things, technical drawings, the concepts of critical dimensions and tolerances, and it got the machine tools industry started. This a major contribution, somewhat forgotten because industry around the world has so thoroughly assimilated it.

And the Toyota system is built on this foundation, incorporating further elements from Taylor, Gilbreth, the engineers at Ford or GM, not to mention TWI. That does not mean that people at Toyota have added nothing there, or that their ability to incorporate these elements into a coherent and efficient whole is negligible. The Machine That Changed The World is a good book, which introduced the term “Lean”, but we should not overestimate the importance. By other names, the approach had already aroused a sustained interest in industry for at least 10 years it came out. My own introduction to the topic dates back to 1980.

Thibaut de Jaegher in turn responded as follows;

@ Michel Baudin
My paper does not deny the contribution of Toyota in the history of production but just reminds readers that there were production systems well before the TPS. Which you also recognize  claiming that Toyota was inspired by American methods, and particularly what I wrote about, to invent its own model.

And an anonymous other reader chimed in as follows:

@ Reglede3
This is very true. Americans, for the purposes of the conflict, however, have pushed the system of standardization to its logical conclusion.

In fact, it was the French who invented standardization (in the late 18th century) in the manufacture of guns (a lock adapting to any gun or butt). It passed to the United States through sales of French guns to the “insurgents”. The English invented the standardization of nuts and bolts.

I have several issues with this exchange. The first is the attribution of inventions to nations. As such “the French,” “the Americans,” “the English,” or “the Japanese” don’t invent anything; inventors are individuals, and sometimes teams. It’s not, “the Americans” who invented the assembly line but a team working at Ford in the 1910s, including Charles Sorensen, P.E. Martin, Clarence Avery, and others. Attributing nationalities to inventions is neither fair to inventors nor useful, because all it does is make the inventions more difficult to adopt outside their countries of origin.

The second point is that both the editor in chief and the anonymous reader are surprisingly casual about historical accuracy, considering that “the French” are known for historians like Fernand Braudel, who make cautious inferences from thorough research. Just-in-Time production of rifles in the Civil War? Interchangeable parts in the Revolutionary War? Come on! As often, the Wikipedia article on the American System of Manufacturing, and its list of references, is a good place to start checking the facts.

Why should we care? Because interchangeable parts technology is the first example of a successful, decades-long government-funded R&D program in the United States, and refutes the widely-held belief  that all innovation comes from the private sector. It was the first in a line of such efforts that, in recent decades, includes the Apollo program and the Internet.

Does it have anything to do with Lean? Yes, but so indirectly as to be irrelevant. The creators of TPS, like Taiichi Ohno, acknowledge Ford’s mass production system, as an inspiration both on what to do and what to change, and Ford’s system could not have existed without interchangeable parts.

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Feb 24 2012

Bodo Wiegand on Shop Floor Management as Leadership Responsibility

Bodo Wiegand heads the Lean Management Institute, which is the German affiliate of the Lean Enterprise Institute. The following is a translation from German of a large excerpt from his  February, 2012 newsletter,  Wiegand’s Watch:

Last week I was invited to a visit a company to discuss the benefits of Lean management with its Board. On such occasions I always ask for a detailed factory tour first. This way, the discussion can be better focused on the company’s actual problems and not get stuck in theory.
My short audit begins before the actual visit. Before turning into the visitor parking lot, I drive around the facility to inspect the grounds. Is it tidy? What do I see? As there marked pathways? How much material lying around? How many employees, forklifts, trucks and cars are moving around? This is my very first impression.
In the actual plant tour, I know they will not show me the problem areas of the company, and that they will keep me as much as possible on a visitor path is. However,  by saying that I would like to go from customer to supplier, I usually get to see what I need. So we follow the value stream from back to front.
The way to Shipping usually reinforces what I have seen outside:  if it is messy outside, with no marked pathways or areas are selected, heaps of materials are piling up, and  cars and trucks randomly parked, what else can I expect in production?
Far too few pay attention and remember that this is the company’s calling card.
Now, in this case are with me the production manager and the Lean Leader. They explain with pride that they have been doing Lean for two years already for 2 years and have achieved huge success. They have  set-up times in half on several machines. But we were at Shipping and I just wanted to know what products were arriving  today to go out  today or tomorrow at the latest. After questioning the Shipping clerk then we found that two containers that were very important and urgent were just too late.
To my question on how often something like this happens, the production manager answered “Rarely”; the shipping clerk, “Every day.” After a short discussion, the production manager admitted to a delivery reliability of 80%, but he was not quite sure. To my question about lead time the Lean leader proudly answered “In general, about 3 weeks.”
“How long does it take to run through a super hot job” , I asked as a follow-up.
“2 days,” he shot back.
My next question about how many projects he had initiated to reduce the lead time demotivated further, as he had to admit there weren’t any.
Well, for me the lead time is one of the most important metrics in a company is and a priority in the execution of projects. The shorter the lead time, the higher the flexibility, the smaller the stocks, the more stable the process, the less time available to make mistakes, and the more efficient the organization.
But satisfaction with a lead time  ratio of 1 to 10 between hot and normal jobs in German companies is quite amazing. For the hot job to be completed in 2 days, it flows through the company without intermediate storage, is processed immediately and is  carried through without pause, without waste, except of course that the supervisor personally takes the matter in hand. But why is it not always like this for all jobs? Why is the exception and not the rule?
But we moved on. In assembly, the Lean leader explains that they have built up an assembly line, but that it still cannot work to the takt time, and that they have therefore built up behind the line an assembly rework shop for quality problems.
Hello? – Has he really understood Lean?
But even outside of the assembly line you could not overlook the signs of chaos. You saw pallets with several items pulled from the supermarket, but by the pallet-load rather than in the quantities necessary for assembly. The reason was simple. The storage space in the supermarket was insufficient and the supermarket was just too full.
The degree of Lean manufacturing and Lean understanding was close to zero.
Next, I turned my attention to the order fulfillment process. But there, also, they had no clue where to start with takt time, bottlenecks, and inventory. The information boards were full of outdated figures on revenue and absenteeism. Two departments were reasonably tidy and provided with standards that were not followed. Brooms and tools had assigned shadows, but were not actually available. Employees were running around for no apparent reason, or talking in small groups. The production manager didn’t know the supervisor’s name, the clocks were off, some windows broken and lamps without bulbs, etc., etc.
[…]
To avoid any misunderstanding, as I walk through a company, I don’t pretend to understand everything, but I try to get an overall impression. Those of you who walk through production daily must know how to see and should focus their attention on a different theme every day to be a good shop floor manager. But beware! It is a difficult, thorny path – but it’s worth it.

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TaktTimesHomepageLogo

Feb 7 2012

Takt times and falling sales: How to Respond?

Question from Jean-Baptiste Bouthillon on The Lean Edge:

We have all learned that overproduction is muda, and that production must follow the takt of customer demand.
Is there a lean way of dealing with falling sales ? Should we just adjust production to customer takt time or stabilize sales by giving rebates ?
Is it important to level sales and give some stability to production or should we just adjust the production takt time ?

My response:

You question implies that takt time is only a function of customer demand. It is not. When you calculate it, you divide your production time by the demand, which means that it is as much a function of how long you decide to work as of how much you have to produce. Without any change in customer demand, you double the takt time by working two shifts instead of one.

The takt time of a production line is the time that elapses between two consecutive unit completions when the line runs. It is not the rate at which customer orders arrive.

So how do you respond to falling sales?

You have to distinguish between fluctuations in sales, for which you should not change the pace of production, and major changes, for which you should.

Once you have set up a large assembly line to work at a takt time of 57 seconds, changing it to 60 seconds is a major effort, involving the balancing of tasks among stations and adjustments in part supplies. In car assembly, unless you are hit by something like the Fukushima earthquake, you don’t do it more than once in four months, even if you are Toyota. During this period, you use heijunka to respond to fluctuations in mix, and adjust overtime for fluctuations in total volume.

If you have a major downturn, you have to reduce production, and the challenge then is to do it without going bankrupt while retaining the work force you spent so much time and effort developing.
It is in such times that having your money tied up in inventory can bankrupt you. When the recession hit in 2008, management in manufacturing companies suddenly took an interest in working capital, but it was too late. Downturns come brutally, and it is when they occur that you must be ready.

Keeping your work force intact and prepared for the next upturn is just as essential. So you stop using temps, cut all overtime, go on four-day weeks, or three-day weeks, and use the available time to solve nagging engineering problems, experiment with new technology, etc. I remember an auto parts plant in Japan, in which recession time had been used by a team to build in-house a pick-to-light system with their own AGV out of Creform. Even though they did not explain it, you could tell that they would know exactly what to require from vendors and how to deploy this technology when the upturn came.

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Occam chooses a razor

Feb 2 2012

Occam’s Razor, Value Added, and Waste

The manufacturing people I know are not fond of theories. They prefer to be on a shop floor with oil mist in the air and machines banging away, observing and acting on the actual situation, than in a conference room, drawing boxes and arrows on a white board, calling it a system and arguing about it. Theories, however, are not a luxury. We need them to structure, organize and focus our thinking about the reality we perceive. Pascal Dennis calls them mental models, and, as Georges Matheron used to say, nothing is as practical as a good theory. A good theory is sophisticated enough to solve real problems, yet simple enough for people  to understand and apply. This is a tall order. To fulfill it, you must not only be inclined to abstract thinking, but you must also have the time to do it, and the ability to communicate.

And there are theories on how to make theories, such as Occam’s Razor, which says that,  among competing theories, you should use the simplest until you have evidence to prove it false. Scientists, engineers, medical doctors, and cops do this all the time. If you make a theory more complicated than it needs to be for its purpose, you make it more difficult to confirm or refute, apply, and teach. About Lean, Occam’s Razor says that we should not have more hypotheses or concepts than strictly needed, as they would be unnecessary, or  muda. If we had a list of seven categories of waste for building theories, Occam’s Razor might provide the first: Unnecessary complexity.

When you read Jim Womack’s theory of Lean, as expressed in Lean Thinking and replicated in much of the American and European literature, you find that it is based on a concept of value-added (VA) that is more complex than the concept of waste (muda) used in the Japanese literature. Jim Womack’s VA is defined as what “the customer is willing to pay for.” I found no reference to this notion either in the works of pioneers like Taiichi Ohno and Shigeo Shingo, or academic observers like Yasuhiro Monden or Takahiro Fujimoto, whose works are available in English. Even a recent author like Mikiharu Aoki, whose 2009 book on the heart of introducing TPS is only available in Japanese, manages to explain the entire system without this notion. It is also absent from Jeffrey Liker’s Toyota Way. You do find occasional references to “value-adding work” in the Japanese literature, but always to designate activities that physically change materials, which is not the same as Womack’s VA. If they don’t need this concept, do we?  or is it a violation of Occam’s Razor?

The confusion about VA is reflected in the large amount of questions and requests for clarification that every mention of it generates in discussion groups. VA sounds deep, and everybody wants to make sure they understand what it is,  how to recognize it, and how to separate activities among “Value-added,”  “Non-value added but necessary” and “Unnecessary.” In particular, the distinction between “Value-added”  and “Non-value added but necessary” would be useful if there were differences in the actions taken about these two categories of activity. Let us take two examples:

  1. Fastening two parts with a screw is usually put in the “Value-added” column. About this kind of operation, first you make sure it is effective, meaning that you use the right screw on the right parts, thread it truly, and apply the right torque. Then you work on making it efficient, so that, for example, no operator has to walk six feet back and forth to pick one screw or fetch a screwdriver.
  2. Revision control on process specs usually goes into the “Non-value-added but necessary” category. A customer would not be thrilled to pay for it, but the plant could not operate without it. First, you want to make sure it is effective, so that the right instructions are posted at each workstation and the right programs downloaded to machine controllers. Then you want to make it efficient, so that engineering changes are either rejected or approved and implemented promptly, without using an army of people to do it.

The two F’s, Effectiveness and Efficiency, are what you pursue in both cases, in the same order. Several people have tried to explain to me how fundamentally different these cases were, but I still don’t see it. I really don’t care how different the activities may be from a philosophical standpoint. All I am interested in is what you do about them, and if the actions are the same, I see no point in having two categories. One argument I heard is that you do “non-value added but necessary” activities only because you have not yet found a way to eliminate them. But the same is true value-added activities. The fastening operation could be automated, the screw replaced by a rivet, or the parts could be welded together, or the entire assembly could become a single molded part… Just because the operation is “value-added” doesn’t mean you are not trying to eliminate it.

Using just two categories — what you need to do and what you don’t — is not only simpler but these two categories are also easier to tell apart. As we all know, customers’ willingness to pay is only proven by actual payments, and therefore cannot be clearly established for a fastening operation halfway through an assembly line. On the other hand, an operation is unnecessary if and only if its elimination would not degrade performance in any way, and we have Ohno’s list of waste categories to help us locate them. If we eliminate any kind of waiting, for example, we know that we will improve quality, reduce costs,  accelerate delivery, without jeopardizing safety or hurting morale. We don’t need to look anywhere outside the workstation to establish this.

Womack’s VA/NVA analysis bestows the “value-added” label on a small number of activities while branding everything else as “non-value-added.” By contrast, Ohno’s list of waste categories is finite. and everything that is not explicitly identified as waste is accepted as necessary. Whenever this kind of classification is made, it is only valid under current conditions.

By • Management • 14 • Tags: , , ,

Feb 2 2012

How do you build cars in a country with a market of 170,000 cars/year?

Via Scoop.it – lean manufacturing

This is news from the Philippines, where the largest car plant is Toyota’s in Santa Rosa, producing only 30,000 units/year. The article’s author sat in a panel of judges that gave Toyota the Employer of the Year award for 2011. This is what he says about the plant: “When we visited their Sta Rosa plant, the Japanese managers were full of praises for the quality of work of their Filipino workers. Our workers have adapted well to their Kaizen work ethic. We were told that the Sta Rosa plant, which assembles the Vios and the Innova, is one of their most productive plants in the Toyota worldwide network.”
Via www.philstar.com

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Jan 29 2012

The 20-keys approach: a concise description

Via Scoop.it – lean manufacturing

I don’t believe in the 20-keys approach to Lean, but like this article as a concise statement of what it is.
Via www.articlesnatch.com

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