In order to implement a design supporting system which can be applied to offshore structures, the authors have developed the integrated system which was based on product model concept. In the design stage, the system is able to generate product information such as “Function Element”, “Main Structure”, “Part” and so on. In the system, it is mainly considered how the product information is generated. In this paper, the system is revised up to a level of simulating use. In order to realize this, some new concepts are introduced. One is the function to support design modification which is implemented by the use of hierarchy of various product information and by the use of the concept of dimension. Another is the model-based finite element analysis system. In this model-based analysis system, designers can analyze structures in early stage by using “Main Structure”. By using the function to support design modification and the the model based analysis system, designers analyze structures easily and redesign structures easily. And then, the simulation based design can be realized.