History

Mar 17 2013

Toyota’s history rests on key textile invention | Long Island Newsday

Kiichiro and Eiji Toyoda
Kiichiro and Eiji Toyoda around a loom

See on Scoop.it – lean manufacturing

It was a single thread that gave a man a dream, created a little history and displayed the talents of a remarkable mind and a family with resourcefulness in its genes.

Sakichi Toyoda wasn’t all that interested in fast-moving machinery, just machines in motion. It’s how the Toyota Production System began. It’s how an inventor with a sharp eye and even sharper mind built an empire…

 

 

 

 

 

Michel Baudin‘s insight:

A summary of Toyota history with the usual omissions:

  1. Automatic shuttle change. The ability to stop when thread broke was not the only innovation of Toyoda looms. Automatic shuttle change was equally important, not just to looms but as a forerunner of autonomation, the Toyota approach to automation.
  2. The German connection. Toyota learned much about car technology from Germany through Kazuo Kumabe and his research team, in particular reverse-engineering a 1936 DKW. The concept of Takt also came from the German Junkers company via the Mitsubishi Aircraft plant in Nagoya.

See on www.newsday.com

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Nov 12 2012

Takt time – Transfer from Germany to Japan in World War II

In Americanization and its Limits, p. 325, the sentence “In February and March 1942, visiting engineers from the German firm Junkers lectured to Japanese aircraft engineers on high-volume manufacture of fuselages and engines.” made me wonder how, in the middle of the war, engineers just “visited” from Germany. It’s not as if you could then hop on a plane in Berlin and land a few hours later in Tokyo.

According to Wikipedia, until Germany invaded Russia in June, 1941, Japanese and Germans visited each other by riding the Transsiberian railway, from Moscow to Vladivostok, which took a few weeks. After that, the only way to travel was by blockade-running submarines, and only six such trips occurred, carrying in total 96 people from Germany to Japan, and 89 in the other direction.

According to the 1946 US Air Force report on the Japanese aircraft industry, passage of materials by rail stopped after Germany attacked Russia, but passage of personnel continued. This is surprising, and it is difficult to imagine how Germans could have allowed to travel that road, but Japan was not at war with Russia until August, 1945. It had a neutrality pact with the Soviet Union, which must have allowed Japanese citizens to travel to Moscow under diplomatic cover, and then on to Germany through a neutral country like Sweden or Turkey.

Ernst Udet visited Japan, its air force and its aircraft industry in 1939. Early in 1941,  the train was still available  and General Yamashita — future “tiger of Malaya” hanged as a war criminal in 1946 — spent several months in Berlin. He brought back 250 aircraft technicians, engineers, and flight instructors. Given the timing and arithmetic, there is no way the vast majority of these 250 could have returned to Germany before the war ended.

The people who visited Mitsubishi aircraft must have been from that group, and must have been available for more than a lecture. My guess is that they stuck around to help Mitsubishi implement their Taktsystem. These people’s direct knowledge of the Junkers system is also as of 1941, before forced labor.

The JMA (Japan Management Association) currently is a large consulting firm in Japan. Shigeo Shingo worked there, and it is also where Nakajima coined the term TPM. The JMA already existed during the war, and, after the war, was instrumental in propagating techniques from aircraft manufacturing to other industries.

According to the same source, “Even in the early 1960s, the Japanese market for cars remained small and assemblers wanted to produce a variety of cars. The companies preferred to accommodate many types of cars on a single line, and consequently emphasized the need to equalize the cycle times of all production processes. This was rather similar to the situation at aircraft companies during the war…”

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Nov 11 2012

Takt time – Even more about origins in German aircraft manufacturing

Earlier this week, I ran into John Paxton’s 2008 paper called Myth vs. Reality: The Question of Mass Production in WW-II, in which he makes a convincing case that production methods were far more advanced in the US aircraft industry than in Germany or Japan. It is really not in doubt. The point in trying to understand the Junkers Taktsystem is simply as one of the sources of TPS. World War II German and Japanese engineers could design advanced planes, like the first jetfighter, the Messerschmitt 262 that you can see in the Smithsonian today, or the Mitsubishi Zero. But, in production, they could not come anywhere near the one-bomber-an-hour performance of Ford’s Willow Run plant.

Yesterday, I was able to go to the main library at Stanford University, where they have about one foot on one shelf in the basement with books on the German aircraft industry in World War II. including in particular Lutz Budrass’s work on the subject and Holger Lorenz‘s Kennzeichen Junkers. Budrass’s book is a forbidding 1,000 pages of small print with a few grainy pictures, long on armament policies and politics, but short on technology:

Lorenz’s book is much more accessible and contains many high-quality photographs, which contradict Paxton when he says:

“Photographs from the era show this  difference. Classic photos from Vickers and DeHavilland (British) and Junkers and Heinkel (German) production facilities show  isolated aircraft in ‘final assembly’, in  stationary jigs, being assembled by ‘work  gangs’, embodying the ‘craft production’  process. In contrast, photographs from  Grumman, North American, Republic, and others show rolling final assembly processes, with aircraft moving from station  to station, much like Model T assembly  twenty years earlier.”

What Paxton writes is not consistent with what little I have seen about  the Junkers Taktsystem, and it is not consistent with the photographic evidence either, which shows that, at Junkers, the final assembly methods in the 1930s were eerily similar to those today for airliners, as you can see in the following side-by-side comparison:

Junkers clearly had a rolling assembly line, albeit one that, unlike the Boeing 737 line, was not continuously moving, Otherwise, the similarities extend even to the kits of parts that are rolled over to each plane. Of course, this is Junkers, not the whole of the German aircraft industry at the time, but Junkers is the one we are interested in, because of their Taktsystem and their transfer of this method to Mitsubishi aircraft in Nagoya, through which it reached Toyota. Other companies used a variety of methods. As we can see on the following picture Heinkel 111 bombers appear to have been assembled on fixed stations in 1939, but Messerschmitt fighters on assembly lines in 1943:

These and more pictures of German aircraft manufacturing before and during World War II are available from the Bundesarchiv Picture Database.

Upstream in fuselage assembly, the comparison looks as follows:

In 1934, for Ju-52 fuselages, Junkers used a nose-to-tail assembly line; in 1940, for the Ju-88, a side-by-side line. Today, Boeing 737 fuselage assembly, Spirit Aero in Wichita, KS, appears to be using parallel fixed stations. Fuselage assembly in this context, however, is limited to fastening together sections that have been assembled separately, with automated riveting.

Paxton’s article contains other assertions that are also difficult to accept. He claims, for example, that the abundance of cars in the US spread mechanical skills throughout the population and that these skills made it easier for large numbers of workers to learn how to build airplanes. He quotes the following statistics for the number of people per vehicle in different countries in 1926:

  • Australia:  30
  • China: 31,871
  • Japan: 1,789
  • Britain:  49
  • France:  54
  • Germany: 194
  • Italy: 353
  • United States: 6

The US was the only country in which almost every family had one car, and American cars of that era were designed to be maintained by their owners. They came with a kit containing the necessary tools and instructions. The US aircraft industry during World War II, however, is known to have employed women in large numbers, as in the following photo of  women installing fixtures and assemblies to a tail fuselage section of a B-17F Bomber (Library of Congress).

If do-it-yourself car maintenance pre-trained World War II aircraft workers in mechanics, then car maintenance must have been done by women. Single women in isolated farms certainly had no choice but to maintain  their cars and tractors, but, in the culture of the 1920’s and 30’s, it is difficult to imagine that women who had a man at hand didn’t delegate changing spark plugs to him rather than learn it themselves. Paxton’s article also asserts that German aircraft production required skilled craftsmen, but most of it during the war was done by forced laborers from occupied countries who were not trained mechanics or machinists.

On the other hand, the article fails to mention two obvious reasons for the superior performance of aircraft manufacturing in the US:

  1. Among all the belligerents, the US was the only one with aircraft factories that were out of the enemy’s range. Germany’s ABC program, on the other hand, had defense against air attacks as a central design consideration. Whatever you do to spread out the facilities and protect the supply chain from bombs does not help you in productivity or quality. The Junkers factory in Dessau was bombed in 1944.
  2. The US aircraft industry in World War II had a highly motivated work force. Not only were these manufacturing jobs the best these women had ever had, but they knew they were producing equipment for the men in their lives who were fighting for a cause they believed in. By contrast, in Germany, Rosie the Riveter’s counterparts were Polish or French workers building bombers against their will for the worst thugs in history, and they would have been happy to see these planes crash on take-off. In addition, most of them didn’t speak German.

The picture that emerges from the documents I have seen so far is that, in the late 1930s, Junkers had organized production in what is now called pulse lines. Final assembly was divided into operations of balanced durations, so that the planes didn’t move during operations but moved forward in unison at fixed time intervals, with upstream processes and the supply chain organized to support this mode of operation. And this is the Taktsystem that was taught to Mitsubishi Aircraft by Junkers engineers in 1942.

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Nov 6 2012

Takt time – Early work at Junkers in Germany

In the TPS Only discussion group on LinkedIn, Joachim Knuf provided the following information, to which I have added a few illustrations:

“Junkers was building an aircraft for infantry support in 1917/18, the J4. After building airplanes in a handcraft mode for some years, this was the first attempt to meet larger demands. Junkers was known for not simply designing a product but the production process along with it. Clearly very lean and practiced by Toyota.”

The founder of the company was Hugo Junkers (pronounced ‘yoonkerz). He died in 1935 and was in no way affiliated with the Nazis, who took away his company and later besmirched his name by claiming association with it. Because the company still bore his name, it is linked in the minds of World War II forced laborers with their experience.

 

“The J4 was build in modules, incorporating components delivered from outside vendors, incorporating fixtures, templates and gauges for economic benefit. Subsequently, the F13, build in 1919/20 as the world’s first civilian passenger plane, was designed from the start with modular manufacturing in mind. This plane was built for customers around the world, with production numbers as high as 60/month.”

The only surviving J4, at the Canada Aviation and Space Museum.

 

 

 

Junkers F13 in 1925.

 

 

 

“Production was organized to an overall completion schedule. As a result, completion of modules had to be structured and synchronized. Final assembly was organized into six phases, performed at specific fixtures. Highly specialized work teams had a set amount of time to complete their fixture-based task, then moved on to the next fixture to repeat the job, followed by another specialized team (what we think of as a caravan system these days). The increment was the ‘progression interval’ (Fortschrittszeit). Airplanes/modules stayed in place. The result was a finished plane every 9 hours. This approach was shared with Junkers facilities working in other industries.

By 1926 this system was developed to the point that subassemblies could be produced off the main assembly and connected to it with moving lines that moved at set intervals. These intervals were then referred to as ‘Takte’ (plural, ‘takt intervals’). With the new W33/34 (first East-West Atlantic crossing in 1928), there was interest in the US to produce the plane in license, in preparation of which Junkers developed a complete production plan to allow large-scale production, identifying the most economical methods. At that point Junkers had 40% of the international market share. Some years later, Lufthansa orders for the new model Ju 52/3m required the further refinement of the ‘takt method’ (Taktverfahren), incorporating new technology and equipment.”

Junkers W34 at the Canada Aviation and Space Museum.

 

 

 

 

“After 1933 (and the nationalization of Junkers by the Nazis) this allowed the mass production of airplanes in serial assembly. To produce the required numbers of planes, eventually also using forced labor, Junkers began constructing large subassemblies in decentral locations within 20 miles of the main assembly facility, delivered just in time. Major subassemblies then moved down a ‘takt avenue’ (Taktstrasse) from station to station, remaining a uniform, prescribed ‘takt duration’ (Taktdauer) in each, creating the Junkers ‘Airplane High Volume Series Production to the Minute’ (Flugzeug-Grossreihenfertigung auf die Minute). Changes in takt were used to adjust production volume to demand. Continuous improvement was an integral aspect of this system (which also certified workers on their self-inspection skills).”

A 2010 video entitled Fischertechnik Taktstrasse mit Sortierung depicts a “Taktstrasse” as a transfer line.

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Nov 2 2012

Takt time: where this strange expression comes from

In the TPS Only discussion group on LinkedIn, Casey Ng posted the following:

“It is quite clear that Takt is a foreign word (外来語) to both English and Japanese.
Its origin could come from German : Taktzeit.
Refer to “Walking Through Lean History” by Jim Womack ( President and founder of Lean Enterprise Institute:

‘By the late 1930s, the German aircraft industry had pioneered takt time as a way to synchronize aircraft final assembly in which airplane fuselages were moved ahead in unison throughout final assembly at a precise measure (takt) of time.’

Therefore, Toyota could have adopted the term and application from Mitsubishi who had technical link with the German in aircraft manufacturing.
But Toyota did breathe new life to the concept of takt by integrating it to the flow principle and inventory reduction of JIT. Therefore, any attempt to implement JIT without proper understanding of takt with Taiichi Ohno’s precise definition of takt time could fail.”

To which Bertrand Chauveau added:

“Takt is a German word

Casey, you are right. It is a German word used in music to describe the rhythm. Mitsubishi brought it back to Japan. Association of Japanese manufacturers deployed it throughout the industry. Thus Toyota adopted and adapted the concept to their production.”

And Frederick Stimson Harriman:

“Regarding the German origins of “takt,” I have never heard any of the Japanese consultants I worked with say where they thought the origin was, but a consultant from JIPM did say to me once that Shingo used the term, and so Bertrand’s explanation makes sense.”

Following are the results of my own research into the matter:

Takt is indeeed a German word, designating a bar on sheet music, but also an engine stroke as in Viertaktmotor (four-stroke engine), and the interval between trains on a line where they run regularly (picture by David J. Anderson), as shown below:

Lean implementers in Germany today, however, are just as confused about it as Americans, and I have heard some refer to Takt as the process time.

But how exactly did “Takt” migrate from Germany to Japan? I think the key reason the Japanese consultants Frederick worked with didn’t dwell on it is that it happened during World War II, and that Japan’s war time alliance with Nazi Germany is not a source of pride.

Digging further on the input from Casey and Bertrand, I found in Americanization and Its Limits a chapter by Katsuo Wada and Takao Shiba reporting that the military aircraft arm of Mitsubishi learned about the German “Takt system” from Junkers engineers in 1942, and had implemented it in the Nagoya works in fuselage assembly by 1943, under the name of zenshinshiki (前進式?). From a contemporary observer’s description, it looks very much like the pulse line system currently used for military aircraft at Boeing, with fuselage sections assembled at fixed stations and moved at a fixed interval — the Takt — to the next station.

This is to be contrasted with the moving assembly line concept used for aircraft also in World War II by Ford in Willow Run, MI, for the B24, and currently by Boeing for commercial aircraft. And it is not the same concept as takt-driven production today. But there are also accounts in German Aircraft of the Second World War of the German aircraft industry using moving lines for subassemblies during the war.

The Nagoya location of this Mitsubishi plant may not be coincidental to the transfer of the term to Toyota, which is still headquartered in that area. It may have been carried in the heads of unemployed military aircraft engineers joining Toyota after the war.

For the German part of the story, in German Aircraft of the Second World War, J.R. Smith and A.L. Kay, in their discussion of the Ju-88, explain “In August 1938, Ernst Udet laid down the Takt system of construction for all large state-owned firms such as Junkers and Arado…”

A Ju-88 flying in 1936

I also found the following picture of a Ju-88 assembly line in 1941, which suggests that the fuselages move sideways between operations rather than nose-to-tail:

Ju-88 Assembly Line in 1941

This is where the trail ends for now. Udet committed suicide in 1941, and was therefore not involved in the transfer to Mitsubishi. I have yet to find a detailed description of the Junkers “Taktsystem.”

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