This paper illustrates the advantages of a computerised product model of a ship, employed during the early stage. Cost items associated with various phases of the ship design process are reviewed, and some problems commonly faced in management of the design information in concurrent engineering are discussed. The basic principles of the NAPA product model concept, called the Ship Model, are presented, and some practical examples of the possibilities are given. Enhancement of the functional design, improvement of basic design efficiency and speeding up of the detail design are illustrated by examples from practical work at shipyards.