Interactive Optimization of Bulk Sugar Deliveries

Abstract
An interactive optimization system for planning bulk deliveries was implemented by Suiker Unie, a farming cooperative that processes about 60 percent of the Dutch sugar beet crop. The bulk delivery problem differs in several aspects from the standard multi-depot vehicle-routing problem: trucks deliver full loads to each customer and can reload at any one of five factories. Loading the trucks is very time consuming, and at each factory trucks can only be loaded one at a time, so that the problem includes both scheduling and routing. Since September 1991, the planners of Suiker Unie use the system to interactively determine and adjust daily schedules. In addition to the improvement of the efficiency and quality of the planning process, the use of the system turned out to yield about seven percent savings in operating costs.