Whilst I am certainly no expert on the subject my understanding was that Toyota realized because of the chip manufacturing issues after the earthquake and tsunami that it was imperative they hold a stock of items that couldn’t be outsourced to another manufacturer and or location in a timely fashion.
That is, if a key component had a unique supplier then they had to revise JIT plans to include enough stock for a realistic restart time for that unique manufacturer should they have a catastrophic issue. Tires and alternators can be manufactured at a variety of locations and by a number of manufacturers comparatively easily and quickly so JIT holds up well for those kinds of components. Microchip manufacturing is done in very limited locations and has massive lead in time and setup costs so needs to be treated differently within the model.
Of course still having the stock you need to keep manufacturing doesn’t get around all the other knock on effects the world has seen. If you can’t get your goods transported then having them made but in the wrong location is as bad as not having them!
Yep, that is the standard inventory management model. 4 quadrant matrix from sole source/strategic to general commodities/multiple manufacturers and then a dedicated inventory/ordering strategy for each. The issue here is that the low value driver chips that had alternative suppliers are being smashed for orders so there is nothing to find anywhere. I remember having multiple suppliers for DRAM chips for instance and yet the whole industry had problems delivering. We were pushing the engineers to qualify more suppliers just to get some options and that took R&D effort as well taking them off other projects.
Just checked the current market and there are 5 main DRAM manufacturers now. The top 3 with 78% market share and top 5 have 98%. Qualifying 5 suppliers for each part number used is a lot of R&D effort.
Samsung Electronics Co. Ltd.
SK Hynix Inc.
Micron Technology Inc.
Nanya Technology Corporation
Winbond Electronics Corporation