An interesting insight into Tesla's assembly and delivery process over at Wired, here.
Tesla is testing every car they build with a battery of tests which takes a whopping 5 hours to complete. This compares with the end-of-line testing of a true high volume mass production auto plant, which takes typically several minutes. At the end of the assembly line, the completed car is run on a rolls machine (chassis dyno) which takes the car through an automated test sequence which spot checks the engine, brakes, transmission, and other systems. There are also final visual inspections.
And that's it. In a modern plant, the quality checks and reliability are built into the assembly process and design itself. Most cars fire up at the end of the line and are ready for a consumer to drive them 150,000 miles.
If Toyota, for example, took 5 hours to test and quality check each Lexus they built, they would not be able to produce many cars, and the plant would not make money.
Is Tesla's extensive end-of-line testing due to a lack of confidence in upstream processes and parts?
If Tesla hopes to be a major player, they will need to increase throughput and reduce in-plant time. They won't be able to check each car for 5 hours.