Decade ago, I read a case study about how a major cell phone manufacturer got out of making phones after it lost most of it's customers because "just in time inventory management" failed for a duration (few months) due to a supply issue further down the chain. It was great until snag hits[1].
If their supply problems persisted for months do you really think it was JIT that killed them? People with a negative attitude to JIT tend to treat it like its equivalent to penny pinching. Its quite the opposite. It means taking a really realistic attitude to the supply chain, and tuning for its potential strengths and weaknesses.
JIT was part of its failure, but certainly not all of it. The other significant problem was purchase consolidation, consolidation is a "desirable" for JIT but not a requirement. Consolidating to one supplier certainly make you a bigger customer and thus more negotiation power, but when the lone supplier choke, you choke also.
I think all of us here know, finding new supplier is not always an easy task, so I don't need to get into that issue.
JIT (in ideal form) gave the system no slack - the parts arrive when they are needed on the line. Literally, the parts come off the truck on the dock and go directly to the production line. Great, you don't need a warehouse; but problem will start immediately when thing(s) doesn't arrive at the moment it is needed. The hero who pushed that will have a duration to brag about zero inventory carrying cost -- until production line stopped for lack of parts.
Besides the risk of non-arrival, to use JIT, ERP (Enterprise Resource Planning) likely is the most needed companion. While ERP software is a great tool when it works, one problem with ERP is that it casts your processes into concrete. Minor change in the process could be huge headaches. For example: We can't get this single piece in the box packaging, let's switch to three bags in the box. Such change could result in major rework of different parts of the ERP system (not software code change but configuration change, new forms, new supplier records to add, etc., etc.). We all know that software modifications could be done over lunch and then it could take weeks to flush out one tiny piece alone.
So one can see the web of problems... No, JIT alone didn't cause it, it just made the issues more immediate and made the issues worst.
... (joke of the moment)...
As he lay on the gurney being rolled into the operation theater, he heard the doctor saying to the nurse "don't worry about us having no liquid stitch, the truck with the liquid stitch resupply is scheduled to arrive at the hospital dock 10 minutes before we have to close his chest up"...