Which rotation will a barge make? Should it first make a call to unload and next one to load? Or is the barge governed by fixed window agreements? Nextlogic sees this as a restriction and plans every call at the various terminals on the basis of the information provided by the barge operator. More restrictions mean fewer planning options and consequently a less efficient planning. It is therefore important that the barge operator only specifies restrictions as a last resort. This increases the planning options and, ultimately, the efficiency.