The speciality in size, complexity and diversity of structure of the ship has made the production management functions exceedingly difficult, but more essential to the success of the shipyard. It is authors' intention that the shipbuilding industry should apply the systems concept to develop more effective structure of production and modernize the procedure of production management. The authors, by adopting the systems approach to their hull steelworks, have improved the production structure mainly through the tact system and established the wide range of computer system, named COSPAC, in the field of the production management. In this paper, the authors report on the accomplished structure of the COSPAC and the computer programs ABL and EBL that produce the day-to-day schedules of assembly and erection processes.