Question: A small copy shop has a self-service copier. Currently there is room for only 4 people to line up for the machine (including the person using the machine); when there are more than 4 people, then the additional people must line up outside the shop. The owners would like to avoid having people line up outside the shop, as much as possible. For that reason, they are thinking about adding a second self-service copier. Self-service customers have been observed to arrive at the rate 24 per hour, and they use the machine 2 minutes, on average. Assess the impact of adding another copier. Carefully state any assumptions or approximations you make.