Toyota Cutting the Fabled Andon Cord, Symbol of Toyota Way | Automotive News

Toyota is retiring the fabled “andon cord,” the emergency cable strung above assembly lines that came to symbolize the built-in quality of the Toyota Way and was widely copied through the auto industry and beyond.



Michel Baudin‘s comments:
The point of having a cord rather than buttons was that the cord could be pulled from anywhere along the line, whereas buttons require you to be where they are. It is the same reason many buses have cords for passengers to request stops rather than buttons.

Toyota’s rationale for moving to buttons, according to the article, is the desire to clear the overhead space. Another advantage, not stated in the article, is that the alarm from a button is more location-specific than from a cord.

Another reason to use a cord was that you didn’t have to change it when you rearranged the line, whereas relocating buttons required rewiring. But the wireless button technology has made this a moot point.

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And around and around it goes | Bill Waddell

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“Not long ago I conducted an exercise with a client in which two teams of three people assembled a Lego product.  One team of three folks from accounting was given the 500 or so pieces the way Lego presents them – kitted in bags of parts that align with the largely graphic instructions.  Basically, all of the parts needed to make sub-assembly #3, for instance, are in a bag marked ‘3’, and the instructions for 3 show pictures of exactly how all of the parts are to be assembled…”

Michel Baudin‘s comments:

You can do many things with Legos, like our own Leanix™games, and this article shows an example where a team of accountants who were given parts in kits and assembly instructions from Lego performed 40% faster than a team of engineers who were given the parts in single-item bags and only pictures of the finished assemblies.

In drawing far-reaching conclusions from this example, however, Bill is comparing apples and oranges. It was faster to assemble from kits because somebody at Lego had kitted the parts, and the kits were complete and accurate. A fair comparison would require including the time needed for this. Kitting may still win, but not by a 40% landslide.

In a real manufacturing situation, you buy components and materials from specialized suppliers and, if you want kits, you have to put them together before assembly. Whether it is justified or not depends on what you are producing and on the parts you use.

Let us assume you are making custom-configured products on a mixed-flow line, but there is one screw that is used in all configurations. You are better off presenting this screw on the line side in bins than distributing it across kits.

On the other hand, it often makes sense to kit configuration-specific parts off line. It requires less labor overall but, most importantly, the work of kitting is done in parallel with assembly rather than in the final assembly sequence, which can cut in half the start-to-finish assembly time on the line.

Even then, however, you have issues with kitting errors by operators who don’t know the product, kits rendered unusable by a single defective part, and part stealing from kits, which is often done as an immediate remedy to the above.

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Wordless assembly instructions

Having just bought and assembled an Ikea office chair, I couldn’t help but marvel at the clarity off their assembly instructions all in the form of sparse, black-and-white line drawings, without a single word. They are easy to follow, almost mistake-proof, cheap to print, and usable worldwide.

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They should be a source of inspiration for operator instructions in a manufacturing setting, with the understanding that additional instructions are needed, like torque specs on the bolts.

Lean Assembly, Lean Logistics, and Euclides Coimbra’s Changes

My fellow consultant and author Euclides Coimbra has only written two reviews on Amazon, both on July 3, 2006, giving five stars to my books Lean Assembly and Lean Logistics, and commenting as follows:

  1. About Lean Assembly: “Very good book. Full of details. Useful for implementers. Knowledgeable readers can find many info between the lines. A wonderful contribution for Kaizen and Lean knowledge.”
  2. About Lean Logistics: “Following Lean Assembly Lean Logistics is a natural continuation. The style is the same and the information as valuable as Lean Assembly. A must have for any Kaizen and Lean implementer. Lots of details and useful information.”

A few months later, I went to work for him, and grew to appreciate his consulting talents. We parted later on good terms and I considered him a friend.

I just received a copy of his 2013 book, Kaizen in Logistics & Supply Chains, and found much overlap in subject matter with the two books of mine that he previously considered a “wonderful contribution” and a “must have.” I assume he changed his mind because they are not in the bibliography, and I couldn’t find my name anywhere in his book.

New assembly methods at Toyota

Toyota’s latest plants in Ohira, in Japan’s Miyagi prefecture and in Tupelo, Mississippi, feature new approaches to assembly. According to press reports, the Miyagi plant is small, with 900 employees making 250 cars/day for export to the US, with a plan to double output and employment. It was designed to require a minimal investment and be easy to change. The plant started operations shortly before the Fukushima earthquake and, even though it is the Northern part of Japan that was most affected, it resisted well and was able to resume operations about six weeks later.

This is how Barry Render described it:

“The Miyagi factory is designed for advanced low-volume, hyperefficient production, with 1/2 the workers and 1/2 the square footage of Toyota’s 16 other plants. Inside, half-built Corollas and Yaris sit side-by-side, rather than bumper-to-bumper, shrinking the assembly line by 35% and requiring fewer steps by workers. Instead of car chassis dangling from overhead conveyor belts, they are perched on raised platforms. This is 50% cheaper, and also reduces cooling costs by 40% because of lower ceilings. Finally, the assembly line uses quiet friction rollers to move the cars along. The rollers use fewer moving parts than typical chain-pulled conveyor belts.”

Toyota is not providing details, but I have been able to glean some information about it from the press and Barry Render’s blog, on the following features:

This is followed by a few conclusions.

Side-by-side assembly

Side-by-side assembly at Toyota Miyagi

Side-by-side assembly at Toyota Miyagi

I have seen side-by-side assembly at the Volvo Bus factory in Turku, Finland. In the picture of the building below, bus bodies are assembled in the hall on the left, side-by-side under they are mounted on a chassis and move forward on their wheels, laid out front to back in the hall you see in the background.

Volvo Bus assembly building in Turku, Finland

Volvo Bus assembly building in Turku, Finland

Volvo bus main assembly flows

Volvo bus main assembly flows

The ratio of width to length  is more favorable to this arrangement for buses than for cars. A straight assembly line with a front-to-back arrangement throughout would require a long and narrow building and a snaking line would have problematic turnarounds. With cars, the side-by-side arrangement seems suitable for work done at the front or the back of the car, such as installing headlights or bumpers. but less for work that requires access from the middle, such as installing instrument panels or upholstery. The following press picture (AP), however, shows an assembly operation done inside the car body in what appears to be a side-by-side layout. It implies that space for the part cart must be provided between cars, which forces them apart.

Assembly operation at Miyagi

Assembly operation at Miyagi

None of the available pictures from the Miyagi plant shows the raku-raku seat that was a prominent feature of the early 1990s designs and made it easier for operators to work inside the car bodies. Not only is a raku-raku seat an added investment, but it is also easier to use in a front-to-back than in a side-by-side layout.

Raku-Raku seat

Raku-raku seat in a 1990s plant

Modular paint booths

I could not find pictures or sketches of the Miyagi painting system. Following is how CNN Money described it on 2/18/2011:

“…Toyota developed a modular paint spray line. The modules can be built somewhere else and are assembled at the plant in a much shorter time. Advantage: Cost savings. However, you don’t build a modular paint spray line factory somewhere unless you intend to build a lot of paint spray lines. Usually, cars get three coats of paint, usually water-based, and usually each coat is dried with heat. Not in Ohira. Here, the third coat is applied onto the still wet second coat and both are dried together. Advantage: Huge energy savings, faster paint time. Lower expenses…”

Friction roller conveyors

Toyota assembly line new concepts 2011 Miyagi plant Conveyance

Following is how CNN Money described the Miyagi conveyor systems on 2/18/2011:

“Where the car moves along the floor, factories usually have below ground pits that house the motors, chains and gears that keep the line moving. Not in Ohira. Here, the cars move on maybe a foot high conveyor system that is simply bolted into the concrete flooring. Advantage: Cheaper to build, cheaper to tear down and rebuild somewhere else. The line can be lengthened or shortened at will. The assembly line doesn’t ‘grow roots’ as they say in Toyota-speak.”

Note that the sketch shows car bodies without wheels. In this system, the bar supporting the cars forms

A photographs of final assembly at Ohira shows operations done further downstream, with the wheels on:

toyota--ohira-plant-in-japan-front-to-back assembly line 2011

Assembly operations after wheels are put on

In this picture, the floor the operators stand on is flush with the assembly line,  meaning that it is either a classical line with the drive mechanism in a pit under the floor, or the operators are in a raised platform spanning the length of this assembly line segment.

Elevated platform versus suspension conveyor

Toyota assembly line new concepts 2011 Miyagi plant Suspension

From suspension conveyor to elevated platform

The following photographs contrast the suspension conveyor approach as previously used at Toyota with the elevated platform at Tupelo, Mississippi:

From these pictures, it is clear that the elevated platform is a cheaper system to build, but I can see two issues with it:

  1. Flexibility in vehicle widths. The Yaris and the Corolla differ in width by less than half an inch, and therefore the same elevated platform can accommodate both. A Land Cruiser, on the other hand, is 11 inches wider, which makes you wonder whether it could share an elevated platform with the Yaris. The jaws of the suspension conveyor, on the other hand, look adjustable to a broad range of widths.
  2. Ergonomics. Working standing with your head cocked back and your arms overhead is just as ergonomically inadequate in both cases. By contrast, the VW plant in Dresden, Germany, uses suspended conveyors that can tilt the body, which is both ergonomically better and much more expensive:
VW Dresden suspended adjustable conveyor

VW Dresden suspended tilting conveyor


The journalists take on the Ohira plant is that it is intended to prove a design for low-volume, low-cost, high-labor content plants that can be deployed easily in emerging economies with small markets. The designs of the early 1990s instead used more automation to make the work easier for an aging work force, with tools like the raku-raku seat. This is a different direction, addressing different needs. But why build it in Northern Japan rather than, say, the Philippines? It shows Toyota’s commitment to domestic manufacturing in Japan, and it is easier to test and refine the concept locally than overseas.

Spotlight | Business Leaners

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This month in the Spotlight we have Michel Baudin.

Michel Baudin‘s insight:

Troy Taylor, from Western Australia, had some questions. Here are the answers.

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Increasing Subassembly Productivity

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In my time spent onsite with the customer implementing PFEP (Plan-For-Every-Part) and advanced material flow techniques, I often was pulled into other projects. One of these projects was an effort …

Michel Baudin‘s insight:

This is a rare post on assembly engineering, dealing with the layout of subasembly cells for a mixed-flow line. This is the red meat of Lean, ignored in most of the English-language literature on the subject. Kudos to Kelcy Monday for getting involved.

Reading this, I can’t help but thinking of many issues I would have handled differently, but I have not seen the product of the shop floor. In any case, this is the right opportunity to work on, with order-of-magnitude performance improvements at stake, as opposed to the 5% others might have nibbled by  applying 5S on the old layout.

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Takt time: can it be universally applied to all types of production?

This is the question Casey Ng asked in the TPS Only discussion group on LinkedIn. He elaborated as follow:

What are the essential conditions to implement takt time successfully? What are the cases when it fails and if you refer to the fundamental principle of takt and yet couldn’t find the solution? Then what are the exception areas and what alternate solution can be used?

To date, it has generated 43 comments, many with the high level of depth and the implementation examples that are characteristic to this group. It is a new LinkedIn group, with only 118 members — compared with 151,503 for Lean Six Sigma — but passionate and providing meaty technical content. I recommend it in general, and this discussion in particular. Here, I will be including only my own contributions on takt time, and its relevance to the following:


With monuments — the very large machines used for heat treatment, electroplating, painting, cutting of sheet metal, etc. — you usually have to load multiple parts simultaneously in order to meet demand, but these parts often do not have to be identical. I don’t recall anyone mentioning this in the earlier comments, but the parts that you load together can be a matching set rather than a batch. If your takt times are long enough, as, for example, in aircraft production, you can actually process one plane-set at a time, to takt time.

Gigantic products with long takt times

Gigantic products, like oil tankers, with takt times of six months or more, are built out of vertical hull slices made at much shorter takt times in a shop, and then welded together in the dry dock. Pioneered in the US with Liberty Ships during World War II, this is now standard shipyard practice, and enhances of the repetitiveness of the process, applying the concepts of takt time and one-piece flow.

Refueling outages in nuclear power plants

I am puzzled by Todd McCann‘s use of the takt time concept in the context of nuclear plant refueling outages, a problem I had the opportunity to work on 20 years ago in France, not in the US. I don’t know who the top performers are in this area today. At the time, it was a tie between the French and the Japanese, at about three weeks from shutdown to restart for one reactor, which is substantially longer than the 193 hours you were quoting for 2006, assuming that the work continues 24 hours/day, 7 days/week.

The French performance was accomplished by standardization. They had 55 reactors with only two designs, producing respectively 900MW and 1300MW, run by a single company. The procedures were the same everywhere, with any improvement quickly shared. The Japanese performance was based on using techniques from TPM. They had nine different reactor designs, run by different utility companies.

Even though they had the best performance in the world, I saw many opportunities for improvement, based on borrowing techniques from SMED, improved planning and scheduling for materials, tooling, and the 1000+ contractors involved, and operational details. Such a detail, for example, was security. Their procedures were effective at controlling access, but inefficient, with utility employees at all levels spending too much time getting contractors into and out of the facility.

The concept of takt, on the other hand, did not strike me as particularly relevant, given that a refueling outage is a yearly burst of intense activity for any given reactor, as opposed to a repetitive process.

Rate work versus response work

More generally about takt time, most businesses have both what my colleague Crispin Vincenti-Brown called Rate Work and Response Work. In manufacturing, if you do a Runner-Repeater-Stranger analysis of your products, Your Runners and Repeaters are rate work; your Strangers, response work.

Runners are products with enough volume to warrant a dedicated line. Repeaters are products that you group into families that, in aggregate, have enough volume for a line. Strangers are all the other products, including R&D prototypes, sample quantities of new products, spare parts for obsolete products, and any other special request. Even in aggregate, they account neither for a high volume nor for high revenue, but you still must produce them promptly. They require a small job-shop set up with your most flexible equipment, staffed with your most versatile operators, and its own operating policies.

While takt time is fundamental to line design for Runners and Repeaters, it isn’t much use for Strangers.

Non-repetitive operations

I have a hard time seeing the relevance of takt time in the absence of repetitiveness. In an assembly process, the takt time gives you an upper bound for the process time at each operation. As you broaden the mix of products you assemble on the same line, it becomes more difficult to balance the work among stations. Past a certain point, you are better off using approaches like bucket brigades, a.k.a. bump-back system, or even a yatai, which are not based on takt time.

Takt time and its calculation

Outside of mathematics, concepts are not reducible to formulas. Time/Demand is the way you calculate takt time, but it tells you neither the rules by which you are supposed to use that number nor how it maps to shop floor activity.

In mass production plants, managers use the inverse of this ratio: Demand/Time, which gives you the same information. Mathematically, working at a takt time of 1 minute and making 60 units/hour (uph) is equivalent. Yet, you and I know that, depending on whether the manager thinks the plant is producing at a takt time of 1 minute or making 60 uph, the shop floor will be radically different.

If you think in terms of uph, it doesn’t matter if nothing comes out for the first 59 minutes of each hour as long as all 60 come out in the end. If you think in terms of takt, 1 unit will come out like clockwork every minute.

What this says is that there is more to takt time than the formula. This is discussed extensively in Lean Assembly, with the following definition of takt time:

“Assuming we complete the product one unit at a time at a constant rate during the net available work time, the takt time is the amount of time that must elapse between two consecutive unit completions in order to meet the demand.”

As I recall, this is,more formally, the way Ohno described the concept in Toyota Production System.

Takt-driven production as the ideal state

The takt time allows you to define an ideal state, that John Shook and Pascal Dennis call True North, but that I prefer to call takt-driven production. In this state, you perform all operations one-piece at a time with process times that exactly match the takt time, and with instant transfer to the next operation at every beat. Of course, it is never perfectly realized, even on an assembly line. Real lines can only be approximations of it. The point is that it gives us a direction.

All deviations from takt-driven production translate to Ohno’s waste categories, overproduction, waiting, excess inventory, etc. Since any local project that move production in this direction eliminates waste, it can be undertaken with the confidence that it contributes to global improvement and is not sub-optimization.

Chronos, kairos, and takt time

Joachim Knuf : “… The ancient Greeks differentiated between two types of time: chronos (chronological, sequence of intervals, typically of equal extension) and kairos, best thought of as ‘the opportune moment.’ In this case, intervals begin and end under sets of conditions. This concept applies, for example, to healthcare, when next process steps are initiated by a preset configuration of values (patient’s blood pressure, glycemic index, bowel movement), not by elapsed time…”

I had never heard of Kairos, but, if the ancient Greeks made the distinction between Kronos and Kairos, why shouldn’t we? There is a rich toolbox associated with the pursuit of takt-driven production. Where the concept of takt does not apply, we can’t use these tools. As you said, extending usage of the word to Kairos-driven activities just adds confusion. These activities need different tools, and Casey pointed out some of them in his comments on Strangers. Let us keep different words to hang them on.

Video on Lean at ACT Trailers

This morning, I received the following email from a manufacturer of trailers in Indiana, with a link to a Youtube video they produced for their dealers. It is a good case of organizing production around the demand structure. At the end of the video, they acknowledge Bill Waddell for his help. Here is the full message:

From: “Lucas Landis” <>
To: “Michel Baudin” <>
Subject: RE: Context of your video
Date: Wed, 26 Sep 2012 08:08:09 -0700

We are a 13 year old company that manufactures specialty trailers in
Nappanee, IN. As with a lot of manufacturing plants during the end of
the last decade, our company went through a terrible austerity period –
employees were laid off, the CEO was replaced, and a myriad of other
radical decisions were made as a result of the downward economy. Out of
the ashes of that, the founding CEO of the company had been doing a lot
of research on LEAN manufacturing. Because we were more or less
starting over, Steve Brenneman (CEO) decided to implement the LEAN
philosophy to maintain a more sustainable company that could avoid
future pitfalls and offer a more superior product. We are now into our
3rd year of our LEAN Journey and this video documents our Value Stream
process. We created this video to help our Dealers understand our
business philosophy and system. Following a previous Kaizen event, we
are in the process of taking LEAN to the front end of our business,
which means getting our distributors in-line with our process. The
video should explain the rest.

Hope that helps.

Lucas Landis
ATC TrailersMarketing
Phone: 574-773-8341
Fax: 574-773-7769