Investigating tradeoffs between performance, cost and flexibility for reconfigurable offshore ships

Abstract

This paper investigates tradeoffs between technical performance, cost and flexibility level for reconfigurable offshore ships. An offshore ship can be configured with various types of equipment; thus, its base structure constitutes a platform from which several end ship design configurations can be derived. A ship with equipment retrofit flexibility will typically have excess stability, deadweight and deck area to ensure physical compatibility. However, there are complex system interactions that need consideration, such as the effects of flexibility on cost and technical performance. To tackle this problem, we capture technical performance using a multi-attribute utility function, based on a ship's capability, capacity and operability, and utilize a tradespace representation of the system to quantify flexibility using the filtered outdegree metric. Findings indicate that increased platform flexibility does increase capacity, but comes at a complex compromise with operability as resistance is increased, and roll periods become unfavorable due to high accelerations. Furthermore, the analysis confirms the applicability of multi-attribute utility, tradespace exploration and filtered outdegree for understanding the implications of flexible offshore ships.