3 ms·

Because they wouldn't need to shut down factories if they had bigger stock of parts on site.

by junaru 3y ago

riidom 3y ago
I wonder, wouldn't it be more of a question of how much later to shut down. Or in other words, how big is the time buffer you get for not being "just in time"? The article suggests (the way I read it, at least) that it is some fundamental time span, but I feel like it's more like half a day?
- LeifCarrotson 3y ago
  In some (American) automotive plants I've worked in, JIT lifetimes are about 10 hours. The order for a seat or mirror or door handle doesn't exist at the tier 1 suppliers where my equipment gets installed until 10 hours before it is needed. At that point, my PLC gets a request to induct a particular part number and paint color into the manifest, inducts it and acknowledges that request, the machine builds it, laser-marks a serial number onto it, tests it, uploads the test results with serial number to the database, packs it out into a foam-lined box or a dedicated nest and uploads the box barcode to the database, that box gets loaded onto a pallet, the pallet into a trailer, the trailer drives 20 minutes away to the OEM, and the trailer gets unloaded (in reverse order; truck size and the resulting last-in-first-out queue is one of the main drivers for JIT lifetimes) so the parts land at the assembly line just a couple hours before the vehicle they belong to is ready to receive them. You'll notice that this does not leave a lot of wiggle room for anything to go wrong. When I'm physically a 5 hour drive away from the plant, it's not like I can drive to the site, debug a wiring issue, order a replacement widget online - even by UPS Next Day Air Early A.M. - and then install it on-site before holding up literally millions of dollars worth of production. And my little mirror line is just one of hundreds of parts that need to arrive on time.
  - riidom 3y ago
    That was very insightful, thanks! I overestimated my numbers apparently.
  - 0cf8612b2e1e 3y ago
    Do the plants have capacity to store more if they wanted? I am thinking of foreseeable short term disruptions which could break the 10 hour windows. Hurricanes, blizzards, train/truck worker strikes, cargo ship stuck in a canal, etc. For a multinational, those are not black swan events, something of that nature is going to break the pipeline on a regular basis. Potentially for days of backlog. Clearly it must mostly work, but that is some crazy thin margin. I assume whoever works logistics is just perpetually on the edge of a heart attack.
    - sgerenser 3y ago
      Yeah, think of what would happen if they were hit with a global pandemic!

Because they wouldn't need to shut down factories if they had bigger stock of parts on site.

by junaru 3y ago

Because they wouldn't need to shut down factories if they had bigger stock of parts on site.

I wonder, wouldn't it be more of a question of how much later to shut down. Or in other words, how big is the time buffer you get for not being "just in time"? The article suggests (the way I read it, at least) that it is some fundamental time span, but I feel like it's more like half a day?

LeifCarrotson 3y ago
In some (American) automotive plants I've worked in, JIT lifetimes are about 10 hours. The order for a seat or mirror or door handle doesn't exist at the tier 1 suppliers where my equipment gets installed until 10 hours before it is needed. At that point, my PLC gets a request to induct a particular part number and paint color into the manifest, inducts it and acknowledges that request, the machine builds it, laser-marks a serial number onto it, tests it, uploads the test results with serial number to the database, packs it out into a foam-lined box or a dedicated nest and uploads the box barcode to the database, that box gets loaded onto a pallet, the pallet into a trailer, the trailer drives 20 minutes away to the OEM, and the trailer gets unloaded (in reverse order; truck size and the resulting last-in-first-out queue is one of the main drivers for JIT lifetimes) so the parts land at the assembly line just a couple hours before the vehicle they belong to is ready to receive them. You'll notice that this does not leave a lot of wiggle room for anything to go wrong. When I'm physically a 5 hour drive away from the plant, it's not like I can drive to the site, debug a wiring issue, order a replacement widget online - even by UPS Next Day Air Early A.M. - and then install it on-site before holding up literally millions of dollars worth of production. And my little mirror line is just one of hundreds of parts that need to arrive on time.
- riidom 3y ago
  That was very insightful, thanks! I overestimated my numbers apparently.
- 0cf8612b2e1e 3y ago
  Do the plants have capacity to store more if they wanted? I am thinking of foreseeable short term disruptions which could break the 10 hour windows. Hurricanes, blizzards, train/truck worker strikes, cargo ship stuck in a canal, etc. For a multinational, those are not black swan events, something of that nature is going to break the pipeline on a regular basis. Potentially for days of backlog. Clearly it must mostly work, but that is some crazy thin margin. I assume whoever works logistics is just perpetually on the edge of a heart attack.
  - sgerenser 3y ago
    Yeah, think of what would happen if they were hit with a global pandemic!