Design Evaluation Methodology for Ships’ Outfitting Equipment by Applying Multi-criteria Analysis: Proper Choices Analysis of Ballast Water Management Systems

All ocean-going ships must be outfitted with adequate ballast water equipment in compliance with Regulation D-2, Section D, Standards for Ballast Water Management, International Convention for the Control and Management of Ships’ Ballast Water and Sediments, promoted by the International Maritime Organization. However, it is difficult to choose the appropriate equipment because the methods used to develop the equipment have similar advantages and disadvantages. Such circumstances make it difficult for two parties who have conflicting priorities, ship designers and ship owners, to choose the most suitable equipment. To address this issue, multi-criteria analysis is effective because it can simultaneously consider several criteria under evaluation as early as possible in the design stage. The aim of this paper is to propose an evaluation methodology for outfitting appropriate ballast water management system (BWMS) equipment by applying multi-criteria analysis combined with the value engineering concept. This combination can directly compare the benefits of function and the disbenefits of cost aspects of a particular system. Nine available methods were evaluated before their installation on ocean-going vessels with a carrying capacity of 300,000 deadweight tons (DWT). The results of the analyses show that, from a ship designer’s point of view, the most appropriate method is one that uses ozone; while, from the viewpoint of a ship owner, the most appropriate method is one that uses a combination of a filter and ultraviolet radiation. Ship designers and ship owners have different opinions. A ship designer emphasizes cost reductions and profit maximization. On the other hand, a ship owner prefers to have a ship outfitted with a system that is easy to operate as well as to maintain.