A method of processing incompatibilities for a transportation plan comprising the following steps: Receiving data which is descriptive of orders, data which is descriptive of available vehicles, and data which is descriptive of available cross-docking locations; reading a set of compatibility types, and a set of compatibility rules with respect to the plurality of orders, vehicles, and cross-docking locations, each compatibility rule specifying a combination of two values which refer to first and second attributes of a defined compatibility type, and being indicative whether or not they are compatible; associating a value with each order, the value being descriptive of the characteristics of the order, such that orders having the same characteristics have the same value associated therewith; replacing the data descriptive of the characteristics by the value associated therewith; and outputting the order data resulting from the preceding step.