4 ms·

Controls engineer here - no, that's pretty normal. I'm accustomed to automotive work, but I believe the electronics assembly lines are similar. The flexible mat

Controls engineer here - no, that's pretty normal. I'm accustomed to automotive work, but I believe the electronics assembly lines are similar. The flexible materials handling stuff (connecting flat flex cables? Applying Kapton tape?) is indeed super impressive, but the timing is ordinary. A sizeable 6-axis robot like those used here has a minimum cycle time of a second or two for the simplest possible "move in, place the thing, move out" operation. They're not ultralight delta or SCARA bots, they're about as fast as a human can control their arm. Also, there's a second or two lost while the pallets moves along and are parked at the multiple stations along the line, you want to design the system to maximize the ratio of useful on-station time to transition time. The line is bottlenecked by the slowest process. You can make a slow station run in parallel - as in the photo at [1] with the 16 stations arrayed around the robot - but that adds a lot of complexity. I'd assume that their requirements were to accommodate up to ~8 minutes for burn-in testing at that station, and that by the empty stations, the software guys ended up only using 4 minutes. You can't make the whole line wait that long, so you spend the extra effort and introduce extra complexity by buffering parts there, but now your process has forked and needs to be merged again - really a pain for tracking suspect parts or tools. All that matters is that you unload each pallet before it needs to move on and replace it with a completed part. Some stations may be doing nothing but running a 5 second electrical test. If there's some station that has to pick up a cable, photograph it, analyze it, contort it by rotating robot joints through large angles, plug it in, and get out of the way, that could easily take 10 seconds. Others may have a human who needs to keep up. Others might be heat-staking a plastic component and need time to blow on the stake until it cools enough to be unclamped. Others might have multi-headed tooling and can connect several different parts all at once. 30 seconds is a nice middling part-to-part value if you've got a few complex operations, a few human operations, and don't want heavy robots slinging your expensive parts around at high speed. I wouldn't have been surprised at a 10-second cycle time, but 30 seconds is still reasonable. A final consideration is that you don't want an entire factory dependent on a single line. If you want to produce thousands of parts an hour, it's much, much better to have 10 identical lines that work at a 30-second cycle time than a single line frenetically thrashing to put out out parts in 3 seconds. If one line goes down, you still have 90% capacity, and can probably catch back up. If your single line goes down, you're in big trouble. [1]: https://s3-ap-northeast-1.amazonaws.com/psh-ex-ftnikkei-3937bb4/images/2/1/7/9/28039712-10-eng-GB/Cropped-1593718166%E9%9B%BB%E5%AD%90%E7%89%88%E8%BF%BD%E5%8A%A0%EF%BC%89%E3%83%97%E3%83%AC%E3%82%B9%E3%83%86%E3%81%AE%E8%A3%8F%E5%81%B4%E3%80%81%E9%9B%BB%E5%AD%90%E7%89%88%E7%94%A8%E3%81%AE%E8%BF%BD%E5%8A%A0%E5%86%99%E7%9C%9F%E2%91%A320200703034521471_Data.jpg https://s3-ap-northeast-1.amazonaws.com/psh-ex-ftnikkei-3937...

ksk 6y ago
Thanks for your insight. Out of curiosity, why don't more of such production lines have dedicated machines that each do one small/simple action and then send it to the next one. It seems many seem to deploy general purpose robots that mimic human hand/arm features (that I would imagine have a higher latency cost in terms of controlling,positioning,etc). Is it so that you can manufacture multiple products with different assembly steps? I work in automation, but of biological processes (vaccines) and we have the same production issues with bottlenecks/capacity planning/down-time mitigation, etc.
- jacques_chester 6y ago
  > Out of curiosity, why don't more of such production lines have dedicated machines that each do one small/simple action and then send it to the next one. Specialising your tools or machines comes at a cost: inflexibility, specifically changeover time between different products. If your machine can only do exactly one thing, the changeover time is "physically replace the machine", which may mean a delay of months. Changeover time is a massive, hard-to-see drag on everything in a factory. The ideal manufacturing machine station can instantly switch its use between any two consecutive products moving along the line. Physically impossible, but ideal. Fully-programmable robots are much closer to that ideal than single-purpose machines. That said, the tradeoff depends on the product/process spectrum. Some products are produced in "job shops", meaning an extremely flexible, high-touch environment, turning out very short runs. Others are worker-paced or machine-paced (which is what the Playstation factory would count as), mostly this is used for consumer goods. These still retain some flexibility, as much as sensibly possible. At the far end are "continuous process" plants. These are very specialised to the product. Bottling plants, chemical plants, oil refineries and so on, where flexibility is not a highly meaningful advantage and the product lends itself to being treated as an undifferentiated flow as opposed to discrete units of product. I recommend Matching Supply with Demand by Cachon & Terweisch as a first book to read. Then follow with the more in-depth Factory Physics by Hopp & Spearman.
NovemberWhiskey 6y ago
>The line is bottlenecked by the slowest process. I visited the BMW factory in Munich back in 2015; at the time it was manufacturing mostly the 3-series models (not sure now). It was a generally fascinating experience; the most interesting piece of trivia was that, when scheduling the build order, they try very hard to avoid putting station wagons ('Touring' model) back-to-back. This was because the build-time of the rear-window assembly on the station wagon took significantly longer than other models due to the rear wiper, and that you would get a literal pipeline stall if you had to do too many together.

ksk 6y ago

Thanks for your insight. Out of curiosity, why don't more of such production lines have dedicated machines that each do one small/simple action and then send it to the next one. It seems many seem to deploy general purpose robots that mimic human hand/arm features (that I would imagine have a higher latency cost in terms of controlling,positioning,etc). Is it so that you can manufacture multiple products with different assembly steps? I work in automation, but of biological processes (vaccines) and we have the same production issues with bottlenecks/capacity planning/down-time mitigation, etc.

jacques_chester 6y ago
> Out of curiosity, why don't more of such production lines have dedicated machines that each do one small/simple action and then send it to the next one. Specialising your tools or machines comes at a cost: inflexibility, specifically changeover time between different products. If your machine can only do exactly one thing, the changeover time is "physically replace the machine", which may mean a delay of months. Changeover time is a massive, hard-to-see drag on everything in a factory. The ideal manufacturing machine station can instantly switch its use between any two consecutive products moving along the line. Physically impossible, but ideal. Fully-programmable robots are much closer to that ideal than single-purpose machines. That said, the tradeoff depends on the product/process spectrum. Some products are produced in "job shops", meaning an extremely flexible, high-touch environment, turning out very short runs. Others are worker-paced or machine-paced (which is what the Playstation factory would count as), mostly this is used for consumer goods. These still retain some flexibility, as much as sensibly possible. At the far end are "continuous process" plants. These are very specialised to the product. Bottling plants, chemical plants, oil refineries and so on, where flexibility is not a highly meaningful advantage and the product lends itself to being treated as an undifferentiated flow as opposed to discrete units of product. I recommend Matching Supply with Demand by Cachon & Terweisch as a first book to read. Then follow with the more in-depth Factory Physics by Hopp & Spearman.

NovemberWhiskey 6y ago

>The line is bottlenecked by the slowest process. I visited the BMW factory in Munich back in 2015; at the time it was manufacturing mostly the 3-series models (not sure now). It was a generally fascinating experience; the most interesting piece of trivia was that, when scheduling the build order, they try very hard to avoid putting station wagons ('Touring' model) back-to-back. This was because the build-time of the rear-window assembly on the station wagon took significantly longer than other models due to the rear wiper, and that you would get a literal pipeline stall if you had to do too many together.