Work centers' capacity must be taken into account. Work centers' capacity may be taken into account, but it's not required. The matrix below shows relative costs for various job-machine combinations. It reduces processing variability. It reduces customer waiting time.
People generally accept it as fair.
It eliminates scheduling problems. Appointments do not have to be all the same length. Dummy resources are needed to solve the problem. The problem cannot be solved. The problem will have multiple optimum solutions.