To establish relation model is to analyze both components that constitute the system and relationships between components statically . to establish system dynamics model is to analyze the relationship of cause and effect between components in the system dynamically . to establish mathematical model is to define the initial values of various inventory strategic variants 建立关系模型，是为了静态地分析系统的主要组成要素及其关系；建立系统动力学模型，目的是为了动态地分析系统要素之间的因果关系；建立数量模型定性，则可准确有效地确定各种库存决策变量的初步值。
