Two approaches to scheduling outfitting processes in shipbuilding

The outfitting process is always a hectic time in the building process of a vessel. The complex nature of the systems on board, the large number of components (50,000+ in technological intensive vessels) and the large number of parties involved contribute to this. It is also characterized by interferences between yard and other parties, disturbances due to delays, and technological constraints and dependencies concerning the installation of the machinery. Currently the outfitting processes are usually not scheduled in detail by yards as the effort is very large and cumbersome. Therefore they rely heavily on the experience of the personnel of the yard and subcontractors. This paper will look into the possibilities to automatically generate an outfitting sequence and planning, based on two approaches. The first is an analytical approach, using a top-down method, which allows an early overview of problematic areas. The second is a mathematical approach, which is based on a bottom-up approach that delivers an optimal sequence of installation based on physical constraints. The paper concludes with a comparison between these two approaches, how they complement each other and how they together can support the sequencing and scheduling of the (pre)-outfitting process.