There is a car factory somewhere in the country, that only produces pink coloured cars. They are all the same and they never vary; they always have the same bodywork and fittings, seats and accessories. Of course, they always have the same engine as well.
But now and again, there is a special order that will come into the factory for a blue car. The blue car is fitted with a different engine and it also has hard black leather seats instead of soft fabric ones and, extra metal trim on the outside to make it look sporty.
The robots on the assembly line are reprogrammed when they have to build a blue car. Sometimes they even build more than one at a time.
One day, when a blue car was being made, the robot that put in the engine wasn’t reprogrammed properly and so it put an ordinary pink engine into the blue car. This mistake went unnoticed because the bonnet lid was shut and the car was rolled out of the factory and tested by the chief mechanic. It started and seemed to be okay, so it was sent to the showroom to be sold. A prospective buyer came along and he took the car for a little drive and was very happy with it so he bought it. After some time, the buyer realised that something wasn’t quite right and so he opened the bonnet. No wonder the car wasn’t quite right; it’s got a pink engine. He drove it straight back to the showroom and got his money back.
The car was returned to the factory whereupon the manager wondered how to fix the problem. The engine could not be changed because it was too expensive to do the modifications and it would be an even more expensive loss if the car was scrapped. The easiest and cheapest option was to repaint the whole car pink. What about the wrong seats and the extra sporty trim? That’s alright, nobody will really notice.