Boeing Moving Line

Boeing’s “PTQ” (Put Together Quickly) videos show a time lapse of an airliner in production. They have been producing the for years – certainly since I was working there.

This one, though, shows something a little special.

When I first started working there, the idea of a line stop was unthinkable. The plane moved on time, period. Any unfinished work “traveled” with the plane, along with the associated out-of-sequence tasks and rework involved.

The fact that the 737 is now built on a continuously moving assembly line in Renton is fairly well known.

But what struck me in this PTQ video is that one of the things highlighted in it is a line stop. It happens pretty quickly at about 1:57.

The video is also full of rich visual controls to allow the team to compare the actual flow vs. the intended flow. See many many you can spot.

10 Replies to “Boeing Moving Line”

  1. Mark,

    That is way cool and thanks for sharing it. To think that just about 10 years ago, most folks said it simply couldn’t be done. The list of clever things they needed to make it happen is long and distinguished too. (I love the stuff that rolls with the plane.) Better yet, most of them were suggested by line workers to help make their jobs easier.

  2. I’ve always been curious about airplane moving assembly lines. I’ve heard many pros and cons from people who work in the industry (it’s not just Boeing who does this).

    Did they really decide (and confirm experientially) that a moving line was better or was it more that Toyota uses moving lines, so to be lean you have to use a moving line?

    I know many lean organizations that do NOT using moving assembly lines… with Lean being all about the culture and management system, whether it’s cellular manufacturing or even healthcare which you could argue is more of an in-station craft-build process.


    1. Mark –
      My indirect recollection about Boeing’s history with moving lines –
      When Shingijutsu first started engaging there, around 1996, Iwata and Nakao challenged them to think about pulling the plane rather than putting it in and out of slant positions.

      Although some enterprising engineers developed a scale model of a concept, in general, the reaction was, to put it mildly, skeptical.
      There were some experiments with components, such as 737 wing spar assembly.

      But Boeing’s culture was still one of looking for the final engineered solution, and working to solve all (or most) of the problems and barriers before they put the plane into motion. There was a huge project to do this around 98-99 on 737.

      The 737 assembly manager then read Henry Ford’s book, and decided to just try it. She got an RV winch, hooked a cable to the nose gear of the last plane on the line, and tried pulling it through the position at takt. She asked “What keeps us from being able to pull the plan continuously?”

      Because the schedule was now visible, and work was, or was not, progressing on schedule, they were able to see sources of delay more easily. Is this the only way to do it? Of course not, but it is a VERY effective way. They worked on problems, one by one, always asking “What is stopping us from flowing the work?”

      So the line as you see it in the video is the result of continuous evolution rather than a single engineered solution.

      A moving line doesn’t make you lean. GM had moving lines for decades. As you point out, it is about establishing a culture of continuous problem solving. And the moving line is a VERY effective tool for focusing people on the “next problem” in the way of the target condition.

      So to answer your question directly, it was largely a result of experimentation, but the original inspiration was a challenge issued by Shingijutsu that festered long enough that a good manager in a position to do so decided to run with it.

  3. I work in the industry and we use this video to show that it can be done in the aerospace industry if required. I like the way it shows tools, systems and principles working in harmony (although I’m sure they have their fair share of problems!) and helps us break the industry paradigms, in particular, “we’re not a car factory”.
    Without knowing the reasoning other than to achieve the principle of flow I couldn’t say why Boeing adopted a moving line but it is the ultimate manufacturing tool for flow. I’d love to speak to some of those that work in it. Airbus utilise a pulse line on A320 wing production with varying success but the beauty of these systems in aerospace manufacturing is that it creates the environment and behaviours required to sustain the culture change. Productuion imbalance and understanding the reasons why is a big problem in aerospace manufacturing and associated behaviours such as travelled work and false flow are the norm.
    Problem solving skills are critical in a moving line enviroment as is standardised work so in an industry that thinks firefighting is a badge of honour this aids understanding.

  4. Mark and Mark
    Having spent a few years benchmarking the 737 production system to then incorporate the lessons into the 767 and 7E7 programs, I would like to add my 2¢ worth. (

    Although the Douglas line building the MD-series was moving, Carolyn did not want to dig trenches in the floor as they did in Long Beach (to install a scaled-up car-wash-like towing system) (easier to ‘go back’?), but she did want to move the line. So they developed and then modified the Motivator (and there is a story there too). She drove the changes, and there were many! She led from the front, setting the example, and it was not all peaches and cream, but she had a vision and made it happen.

    As M.R. mentions, the Shingijutsu did not have many encouraging words for her and her team, but then that was their way. When my team worked to turn the 767 into a moving line, they still questioned it at every opportunity, and rightly so – it is a lot of work to go through if there is not a clear need for it.

    To the point made by both of you: a moving line does not make you lean – but if it is used as a part of an integrated culture shift (look up Carolyn Corvi and ‘Move to the Lake’) to turn an engineering-driven organization to a production-driven organization, the effort can in fact pay-off. Some of the reductions in lead-time and inventory can be explained by other factors (again, a whole different story), but for the Renton plant to go from 22days to 11days, and from three (pulse) lines to one (moving) AT THE SAME TIME(!), something is working.

    And as for the crews on the floor; none of the many team members I spoke with and worked with and learned from would ever consider going back to the old ways. There were a few in the support ranks that were not yet comfortable with their new levels of accountability, but there were only a few. In the video linked here, you catch a glimpse of some of the support team working at their desks with the tail of an airplane moving by behind them. And because of the way the engineering workspaces are installed, you hear (and smell) the production floor all day and can tell if something goes awry before the call for help goes out (yet another story there – for another time). ( )

    Bottom line on moving lines: it is done not so that the product moves, as much as it is done so that it NEVER STOPS moving!


  5. After reviewing Boeing moving assembly lean line design. Boeing has done a great job on assembling there product but, looks like there lacking in ergonomics field.
    After reviewing comments about moving assembly lines and nonmoving assembly lines; it all comes down too a lean assembly line is that of it’s (O.M.S.) Organization management System.

    Organization Management System feeds the right and wrong way of doing ergonomics, lean line set up! It’s not about if the line moves or not!

    Here is a phrase to go by if you what to be lean! (Follow ergonomics you’ll get too lean safely)

    David W. Chitwood
    Humantech S.M.E.
    D.F. Ergonomic
    Chief designer
    Cell, 731-394-0074

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