A DSS used for vehicle routing at the Westland Co-operative Dairy Company Ltd., New Zealand, is providing a spectrum of benefits and business values. Labor hours, required by the schedulers, have been significantly reduced; the schedules they develop are more efficient, the number of truck drivers has been reduced even though the volume of the traffic is increasing, and the Transport Office has a greater flexibility and higher morale. The system includes powerful tools to plan schedules, choose plans, generate alternative plans, and assess alternative plans with respect to the given criteria. The system also allows the scheduler to create routes automatically, minimize the total distance traveled, and manually modify routes created by a model. It also has several classic characteristics that are too seldom actually realized: it leverages the judgment of the DSS user; it has evolved over time through an iterative development process and is being adapted for use in another company. Taken together, these benefits and attributes make the system a rare example of a successful DSS that can provide guidance for the development of other systems in the important problem domain of vehicle routing.