What travel method are you using/planning on using in your model? Do you have an example model with the basic logic in place? Otherwise the possible cases are not apparent from your question:
Do the operator travel together with the freight?
In this case the freight could just stay loaded in the operator.
Do they only transport it to the elevator and another operator will continue on another floor?
In this case a simple process flow could control the elevator. (Travel to origin floor -> Have operator unload into elevator -> Move to target floor -> Wait for pick up)
