Just after shipbuilding industries have released several kinds of large scale of CAD/CAM systems, the necessity of Computer Integrated Manufacturing system (CIM) have been recognized in Japanese shipyards. In the previous paper, a shipbuilding definition system (or a modelling for shipbuilding) was discussed. As the result, a System of Design and Assembling for Shipbuilding (which is called SODAS) was proposed. In SODAS, there are some systems which include ship design system, system of cutting of designed ship structure into pieces and system of assembling those pieces to a ship block. The aim of this paper is to refine assembling system in SODAS. In the construction stage of a ship, a lot of work should be done by using particular facilities in shipyards. Therefore two models are introduced here. One is facility model such as crane, lift-magnet and welding machines. The other is operation model in which operation data such as welding condition, root gap should be managed. An object oriented language on engineering work station Sun-3 is also used to represent a ship and shipyard model.