Shorten the lunch line.
Speed up the lunch line.
You are talking about making the lunch-serving process more efficient, and your example says you are measuring that by how long (presumably) the queue is. So. Improving the serving process means reducing the number of people in the line, or the waiting time on it.
"I'm hungry, dammit. Send in the operations managers!"
Operations management is the discipline of business administration concerned with making processes more efficient. You could read up on it to find out what has been done lately in the area of meal-serving.