“We CAN’T Just Stop The Line!”

I suppose, at some level, that makes emotional sense. After all, the idea is to keep production moving.

But the logical follow-on question is: “OK, so if the team member encounters aproblem that is going to force her to work around things, to do the work in a way that wasn’t planned, what do you want her to do?


6 Replies to ““We CAN’T Just Stop The Line!””

  1. We had a similar situation where we said that we couldn’t just shut a machine down because we detected a defect a number of years ago in one of our operations. Unfortunately (or maybe fortunately), one of my favorite Shingijutsu Sensei’s was asking why we couldn’t. He was standing in the control room and kept hearing beeps that indicated possible defects as detected by sensors near the end of the process. When the Sensei asked why we didn’t stop to process, my colleague replied that “stopping the process actually causes more waste because we then have to scrap the entire web in the machine.” When we did stop the process, it involved a very long and costly re-thread of the machine.

    Without tipping my hat to the company or the process, let’s just say that the process involved coating a moving web with very complex, multi-layered coatings and the web length from start to finish was almost a mile. For reasons of “efficiency,” we also coated a fairly wide web, then slit it down to narrower widths for actual customer use.

    As with most Sensei stories, this one has an interesting ending. So the Sensei turned to my friend and asked ‘Why don’t you just coat the width of web that your customers buy?” What he was getting at was the fact that our quest for mass manufacturing “efficiency” had driven us to design and build machines that actually made it more expensive to stop for defects than to compensate for them in later operations. His counsel was then that we had a long road on our hands to address the principles of Jidoka. Boy, did he get us thinking though.

  2. Maybe it depends on the process. If your making teddy bears on an assembly line then stopping the line for a problem or defect might not be necessary. The problem could be noted and fixed later.

    However, here where I work we make aeronautical equipment. If someone was going to do a work around because of a problem we would want to stop the line immediately. Because we work with small batches in each cell, stopping the line only means we stop one worker doing one small operation. While the rest of the plant can keep producing.

    Like Tom Warda points out. I think it depends on the product and the process.

    On the other hand, the way Toyota uses “stop the line” thinking, it probably improves their overall quality, and it uncovers all problems. ( I’m guessing here. Do they stop any and all of their assembly lines for any problem? )

  3. I’m not sure if it really depends on the product. Let’s say, a line produces 1 Teddy bear/sec., at a dollar each, that might indeed not be worth stopping the line.
    BUT, since you don’t just want to fix problems, but learn about your process and get it to higher levels, I think even an issue with a Teddy bear is worth pulling the Andon and go, see!

  4. (1) Capture the facts about what led her to deviate from the planned work in order that the information does not ‘spoil’ (in place and time).
    (2) Capture her new way of working in order to allow it to become a standard for such situations.

  5. Yes, I would expect the worker to do these things on her own, under the following two conditions:
    (1) If these expectations have been made clear to / agreed with her. In other words: if it has become part of standard work.
    (2) If she has time for it. From a practical point of view I realize this is not always easy since ‘working around’ the problem probably means additional work / attention. And we wanted to keep the line running so there is still the work that she normally is supposed to do. Alternatively she would need to call for help, e.g. the teamleader jumping in.

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