Every port is unique. Although all ports exist for the same basic purpose (to act as an interface in the transfer from one mode of transport to another), no two are ever organized in the same way.Ports may be classified according to: Physical conditions: location (geographical position, man-made or natural harbour, estuary location, difficult weather conditions, tides, etc.) and size (large, small or medium-sized). Use: commercial (general cargo, bulk solids, bulk liquids, oil, break bulk, mixed), passenger, sport and leisure, fishing, mixed, etc. Ownership: private, municipal, regional or State-owned. The Port Authority's role in management of the port: Overall control, i.e. the Port Authority plans, sets up and operates the whole range of services. Facilitator, i.e. the Port Authority plans and sets up the infrastructure and the superstructure, but services are provided by private companies. Landlord, i.e. the Port Authority allows private companies to be responsible for the superstructure and provide port services. Different combinations of port types will therefore give rise to different kinds of organization and different information flows, which means that the associated information systems may differ significantly from port to port. Since this paper relates to the port of Barcelona, with its own specific characteristics, the contents may not always be applicable to other ports.