Incentive Plans are notoriously complex and often contain a subjective element which is out of the control of the target achiever (be they sales or service reps). Companies spend more on incentive plans setup, admin, management and payouts then they spend on Marketing and Advertising. In same cases up to 3 times more! The best approach is to have targets that are completely objective and can be achieved without dispute. Many companies set some targets that are soft or subjective targets which are out of the circle of influence of the sales or service person.