Hello @Jan,
Welcome to FlexSim. We have many tutorials to help you become acquainted with FlexSim. Please check them out.
One thing to note about the process flow that you have created is that there is repetition. Whenever you see repetition in your logic you should consolidate it. In your case I could put all 3 floor storages in a group and have the event triggered source look at the group instead of having a source for each floor storage object.
Another great thing to use is lists. In your case a list would be a great way to randomly select pallets from a queue. There are two ways I can interpret what you want. You would like the fork lift to pick up 3 random pallets and the pallets can come from different queues or they need to come from the same queue. Either way you would use a list to decide where the fork lift needs to go. I went the route of pulling pallets from the same queue. In this case I would have the queues on the list and I will query that the queue has at least 3 pallets in it. Then I can use that reference to pull 3 pallets from the Queue. Since you are loading and unloading 3 items instead of having 3 load activities you can use a subflow to create a token for each item you want loaded and to run through the load activity. This is especially helpful if you want to vary the number of items picked up.
flexsim-pull-from-random-queue_1.fsm
