Many approaches, which to modeling data structure and data behavior for the total shipbuilding, have been made so far. Especially Object-Oriented product modeling approaches have led to some successful results. Data in one product model for shipbuilding is inevitably referenced and manipulated during each phase of design or production activities, and data or manipulation status naturally varies from the original with the advance of each activities. For Object-Oriented approach, it is hard to identify object classes dealing with those variations, and even if once a product model developed, it might be getting much harder to modify it to cope with a new additional phase of activities. This paper proposes an approach, temporarily named Concept-Relationship Modeling Approach, which handles data structure and behavior independently of each other in order to resolve the difficulties above.