A new software model was developed to obtain the desired design/simulation arithmetic by combining arithmetic components dynamically according to rocket motor designers’ design/simulation tasks.This software model could be used to finish a variety of SRMCAD/CS tasks while offering excellent expandability for software system.The purpose of this research is to create a standard and open arithmetic component interface system

whereby a reusable

expandable arithmetic components library and a combined arithmetic components mechanism could be established.In this way

the designers’ tasks of compiling design/simulation arithmetic can be turned to combine dynamically into a desired one using the existing arithmetic components.This software model enables the designers to reuse the existing arithmetic in the arithmetic component library

while maintaining the liberty of designers for easier and efficient work.