Abstract
The weight is associated with stability, strength, and price of an offshore plant. For this reason, the weight is estimated and controlled during all design stages. In shipyards, the weight estimation is firstly made using FEED (Front End Engineering Design) data received from owner. However, the estimated weight has some difference from as-built weight because of several reasons such as rack of design time, low quality of FEED data, improper margin, and so on. That is, such difference is caused by weight estimation uncertainty, and its definition is not firmly defined yet. To cope with this uncertainty, we studied a method for the weight estimation based on the statistical method and the optimization method. This paper presents the result of the method.