Taktzeit

Now and again someone wonders out loud why, in this lexicon of Japanese terms, we have the word “takt.”

I had always passed along what I had heard – that the word was German, short for taktzeit and used in their factories to represent the pace of production. During WWII, the Germans had helped the Japanese set up more efficient production lines, and the word migrated into Japanese usage.

All of this had been anecdotal.

factory_floor07But today I ran across Alan Hamby’s phenomenally in-depth reference site on the German WWII Tiger Tank. Alan has extensive detail on the Henschel Tiger Tank Factory, and in some of the photos are signs indicating the number of the “takt” or production position.

But don’t stop here. Take a look at Alan’s site, and look at how this factory is set up and operated. This plant was set up to produce a Tiger I tank every six hours, and built a total of 1375 of them between 1942 and early 1945. Yes, there is a lot of waste, but bluntly, I have seen 21st century factories making products of similar size and complexity that are far worse than this.

The idea of pacing and balancing production is not new. By the time these photos were taken around 1943, the concept had been proven for over 20 years. Yet when I visit factories today this is a seemingly novel concept. I always wonder why today’s operations managers are not insisting on at least the efficiencies that were achieved by 1935.

Thanks to Alan for his kind permission to bootstrap from his research and use these rare photos here.

Just to be clear, though, having a pace for production does not make a line “lean.” Far from it. But it is a foundational element. It may not be sufficient, but it is (in nearly all cases) necessary. What makes it foundational element for improvement, however, is not so much the pacing and balancing aspect. Rather, the concept of takt time can be used as a way to structure improvement goals and targets in a way that is meaningful to the people doing the work.

We talk a lot (all to much, in my view) about metrics, but tend to think of the things management is interested in – like labor productivity. But the way you get labor productivity is to focus on the takt time, the total cycle time, and the stability of that cycle time. Those are the things that determine how much gets done by how many people. You can measure “labor productivity” all you want, but you can’t change it unless you get down another couple of levels. Fortunately (for us) Reichsminister Speer didn’t figure that out.

 

By the way, just to put things into perspective:

In 1943, Boeing Plant 2 was producing one B-17 bomber an hour, sixteen planes a day, six days a week. They did it by using a paced assembly line and continuously working to simply and improve the flow.

2 thoughts on “Taktzeit

  1. Great post. Was Boeing calculating and working to takt time in 1943 as well or were they simply focused on improving flow and building as many planes as they could? I’m guessing if they could have built more than 16 per day they could have moved them with no problem, right?

    1. Volume 15 Number 1 (Q1 1999) of AME’s Target Magazine has a good, well researched article on the subject. Bill Vogt, a Boeing engineer, got curious about “how they did it” and wrote the article about not only Boeing’s production of the B17 in Plant 2, but Ford’s production of the B24 at Willow Run.

      Boeing did not call it “takt time” but they had a pacing clock and synchronized the pulse of the line(s) to that clock.

      They were very limited by the space available to them. I have walked the floor in Plant 2 (which is mostly storage and some shop assembly today). That limitation forced them to maximize flow and minimize excessive stocks of parts, etc.

      Aircraft, wings, major components all were moved at takt as feeders converged into one another toward final assembly.

      They used TWI Job Instruction and visual work instructions out of necessity due to the rapid expansion and high turnover of the work force.
      Ford did the same thing building B24 bombers at the same rate, with the added feature of using stamping equipment to make pre-formed skin panels to save time.

      The critical key point about takt time is that it is ALSO used to “build as many as you can” in way that systematically identifies the next constraint rather than trying to just rush stuff out the door. In all of the little simulations I do, people are always more productive when they are working to a takt time target than when they are just pushing – even when they are visibly slowed down in comparison to the first run.

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