Next, i study the process control of compositional modeling ( cm ) and a kind of management information about model fragment use, modeling assumption . in this paper, i provide a structural model about model fragment library, and propose hierarchal representation mechanism about model assumption . base on the utility of modeling assumption during qualitative model construction, i build the mapping mechanism from modeling assumption to modeling decision 其次,本文研究了定性组合建模的过程性知识??有关模型片断使用的模型假设信息,从模型片断库的结构出发,提出模型假设的分层描述模型;针对其在建模中的作用,建立了模型假设到建模决策的映射机制。