Help me find the joke of "quality control"

A domestic factory imported a set of equipment, and its shell was like a big oil tank. It broke down after running for a month, and no one in the factory could repair it. I don't know what the problem is. Contact foreign distributors immediately. The dealer sent an experienced engineer who said he wanted 1000 dollars. The director was in a hurry and agreed.

The engineer started the machine and listened for a while, then picked up a piece of chalk and drew a circle in a position of the equipment shell, saying that it was open here, and sure enough, the problem was there.

After the equipment was repaired, the engineer asked the director for money. The factory director felt very reluctant to draw a circle so easily and take away 1000 yuan, but it was hard for him to go back on his word, so he asked the engineer to write a maintenance order.

Engineer maintenance list: 1. Draw a circle with chalk-$65438+0; Second, I know where to draw it-999 dollars.