I have to implement a brewery process in Anylogic. In the second step the beer orders (Agent type: Beer : with the parameter Liters) to go into a cooling process with two machines, one old machine and one new machine. It is allowed for the beer order to be split between the two coolers. I am struggling to implement the split block. The beer order should go to the New cooling machine (capacity: 1400L) if this is available and otherwise the old one (Capacity: 1000L).

I tried to implement the below, but I get a problem in my function. Also, this solution does not take into account if the first beer order was directed to the new cooler and therefore the second one should be sent to the old cooler (to be efficient). I have figured out it makes sense to create the two variables LitersNewCooler and LitersOldCooler, and let these change every time a new agent needs to be split (state variables) but at the moment they do not update. Can you help me understand why?