An ideal point method adopting grey relational entropy to estimate life cycle cost with effectiveness of torpedo

To making the decision of the developing blue prints, ideal point method was selected to estimate the life cycle cost with effectiveness of torpedo. At the same time, the concept of grey relational entropy of the grey system theory was adopted to compute the distance between each blue print and the ideal point (or negative ideal point). The blue print, nearest to the ideal point and farthest to the negative ideal point, is the best one. As an example, four blue prints of torpedo were estimated. The result indicates the practical value of this method.