短文改错（满分10分）

Yesterday, I went to have lunch in a restaurant. The restaurant was such crowded that the food arrived late and the fish was cold. I was on a hurry, so I started eating the food anyway. Several minute later, a server came to me and was asked how I liked the meal. In that situation, he may choose to say honestly that you are disappointing that the food came out cold. However, I choose not to tell the truth. With a smile on my face, I told the server nothing satisfied me. I told lie. But it made the server happily.

什么叫设备检修？其作用和目的是什么？