In my model I have 4 combiners connected to a queue and I use a robot to move the items from the combiners to the queue. The robot also has the ability to carry 4 items at once. As the model is created now, the robot starts moving to the flowitem that first entered a combiner, but as the robot moves it passes over other combiners and due to it can carry 4 flowitems. It picks up other flowitems (that entered directly after the first to another combiner) on its way to pick up the first item. I want to create some kind of priority so that the robot will pick the flowitem that first enters one of the four combiners, and then the second, and so on. How can I create a priority so that the robot always gets the first entered flowitem in a combiner? Is a pull strategy in the queue a good solution and if so, how do you do it?