Taguchi concepts and their applications in marine and offshore safety studies

Abstract

Taguchi concepts have been developed into an engineering method of quality improvement referred to as Quality Engineering in Japan and as Robust Design in the West, which is a disciplined engineering process that seeks to find the best trade-off of a product design. A safety optimization framework using Taguchi concepts is proposed in this paper. An example is used to demonstrate the application of the framework in maritime safety studies. Following a brief review of Taguchi concepts and techniques used in Robust Design, this paper discusses how the Taguchi concepts such as 'quality loss function', 'signal-to-noise ratio', 'orthogonal arrays', 'degree of freedom' and 'analysis of variance' may be synthesized in maritime safety engineering studies. Brainstorming, an integral part of the Taguchi philosophy, is also briefly discussed. Orthogonal arrays are used to study many parameters simultaneously with a minimum of time and resources to produce an overall picture for more detailed safety-based design and operational decision-making. The signal-to-noise ratio is employed to measure quality; in this case, risk level. The loss function is considered as an innovative means for determining the economic advantage of improving system safety or operational safety. Noise factors are considered as any uncontrollable or uncontrolled variables or any other undesired influences. Control factors are the variables that are set by the designers that will characterize the performance as well as safety level of a system throughout its life cycle. The outcomes of this paper may provide the fundamental knowledge for safety analysts to utilize the Taguchi concepts and methodologies. A hypothetical example with simple analysis techniques is used to illustrate how the Taguchi method can be used to extract from expert judgements those factors the experts judge as most vital when they perform risk estimation for a ship with the purpose of determining insurance rates.