QMS is a queue management system that helps you understand and optimize your queue. A queue is a way to coordinate the flow of items or people. 

Imagine a car manufacturing company where the cars are made in five different models in five different colors. At the time of production, one car can be produced in only one color and one model. When the time comes to deliver the cars, the company needs to get the orders of the customers to deliver them in the order they came.