question

I'm not sure I understand enough to make a recommendation, but here are my thoughts.

It sounds like you have 10 types of items, and that you must make this decision for each of the 10 types. Perhaps you want to run the model where you say "how does the model run if I send types 1, 2, and 3 to port 1, and types 4, 5, 6, and 7 to port 2, and the rest to port 3". In this case, you'd need to add one parameter per type (so 10 parameters). Option parameters are the perfect choice, with three options. If you name the parameters in a pattern (Type1Port, Type2Port, etc.), then you can write code to get the correct value based on the type, in the Send to Port field:

Model.parameters["Type" + item.Type + "Port"].value

PortByTypeParameters.fsm

Once you have those parameters set up, using the Optimizer is easy; just add those values to the optimizer, so you can try different combinations of ports, and see which combination is best. The optimizer will try different assignments (perhaps types 3, 7, and 8 will go to Port 1, and types 1, 2, and 9 will go to port 2, and the rest to port 3).

Does that sound like what you want?