My,
I have worked in Automotive manufacturing for 40 years.
build dates changing is a normal situation today.
In the past, cars were built and stored in fields until there was a call for tgat car.
Nowadwys cars are built to order.
The build date is the initial order input, but will move due to many factors.
Paint. Cars are batch painted, it’s more efficient=n5 than building, say two black cars then three green cars, cleaning of lines, paint mixing etc, if yiu order a unique colour or unpopular colour, it can have to wait until there are enough cars for a batch
Parts supply issues. A big issue, if a supplier, due to shortages at their plants, cannot supply enough parts, then the car won’t be built, as even if built, then has to stay in a compound waiting for the missing parts. Sone parts that do have weekly/daily issues are steering wheels, air bags in the same colour as the steering wheel, carpets different colours and pile issues,seats, most leather for example, comes from one dyeing company and supplied out to various trimmers to produce the parts. As it’s a living skin, there can be big issues getting enough parts out if there are for example, barbed wire cuts, or the dye doesn’t flow correctly, as a complete set of seats comes from one batch,myiu can’t have different shades.
non leather also has manufacturing issues.
Electronics. Yes, the chip shortage is being reduced, but is not back up to speed. Also, you do get failures in components, not seen until tested in situ. If a wiring harness has a failure, you can’t just cut the part out and solder a new part in, as the supplier will not warrant the whole harness due to this, so a harness replacement is a complete strip down of the vehicle interior to get the main harness out.
Also, harnesses are now car specific and built in huge wiring boards in Morocco Specific for that car. This weight saving not putting in redundant wiring.
wheels. Each wheel has to be checked for marks, especially alloy wheels. These are not produced in the UK anymore, nor in Europe, but the far east and have to be shipped over.
These are just sone of the many issues in building cars, when you use some 20,000 pieces from thousands of suppliers, problems happen.
Tge manufacturer doesn’t want to stop production as the workforce still have to be paid, plus fixed costs, so every day, cars are moved on a build plan. Add to that the amount of cars that are on the order books due to Covid, the war and Taiwan chip factory fire…..
it’s a nightmare!