I'm trying to have a source in process flow create a token when the inventory falls below a certain value, we'll say 10. I'm open to tracking the inventory in different ways: quantity in a final queue, value in a table, list, etc. This will be part of a very large/complex model that is used a lot, so I am also concerned about computational efficiency. For this reason, I'm concerned that simply executing a decision that checks the inventory every time a new object enters the final queue is going to slow down the model. How would you recommend doing this?