> McDonald's is trying to run an industrial volume process with ingredients subject to contamination and spoilage
You're getting at the heart of it. McDonalds used to use very simple Taylor machines that were very reliable. The only problem was they had to be taken apart, cleaned, and sanitized at the end of every day. That required an extra employee at closing for about an hour, and another employee the next morning to put the machine back together. This wasn't difficult, but it wasn't totally obvious either so it did require an employee who had been trained on how to do it.
McDonald's wanted to save the training and the $10-$20 of labor, and a few dollars of product waste that this was costing them every day, so they asked Taylor to develop a machine that didn't have to be taken apart and sanitized every day. Taylor did that, and the machine got a lot more complicated. It heats itself up to a temperature that will kill bacteria, then cools back down. If there is a power glitch or fault or for any reason that cycle is interrupted, the machine locks out and has to be "repaired."
Also, as part of the daily cleaning and re-assembly of the old machines, all the O-rings and seals would be inspected and lubricated and replaced if they were cut, worn out, etc. Now that doesn't happen so you get more failures of seals, leaks, etc. which can also shut the machine down.
You're getting at the heart of it. McDonalds used to use very simple Taylor machines that were very reliable. The only problem was they had to be taken apart, cleaned, and sanitized at the end of every day. That required an extra employee at closing for about an hour, and another employee the next morning to put the machine back together. This wasn't difficult, but it wasn't totally obvious either so it did require an employee who had been trained on how to do it.
McDonald's wanted to save the training and the $10-$20 of labor, and a few dollars of product waste that this was costing them every day, so they asked Taylor to develop a machine that didn't have to be taken apart and sanitized every day. Taylor did that, and the machine got a lot more complicated. It heats itself up to a temperature that will kill bacteria, then cools back down. If there is a power glitch or fault or for any reason that cycle is interrupted, the machine locks out and has to be "repaired."
Also, as part of the daily cleaning and re-assembly of the old machines, all the O-rings and seals would be inspected and lubricated and replaced if they were cut, worn out, etc. Now that doesn't happen so you get more failures of seals, leaks, etc. which can also shut the machine down.