But how long it takes a particular customer to receive a food order is complicated by a number of other variables. For instance, what if there were 10 cars waiting in line, or it was 12:00 noon, or it was raining? Other factors such as the number of drive-up windows, the training level of order takers, and the number of customers waiting also are variables. Consequently, all of these variables can have an effect on the order time variable.