关键词: 需求知识, 定制产品, 需求分析

Abstract: Multi-granular decomposition and reconfiguration modeling for the requirement knowledge of customized product were performed.The rough set theory was introduced into processing and analysis process.Analysis and simplification method for requirement knowledge based on rough set theory was proposed.The requirement knowledge was evaluated according to the importance so as to guide customization design process.By combining with project execution，the method was applied in the requirement knowledge expression and analysis of air separation to illustrate the applicability and effectiveness of proposed method.

Key words: requirement knowledge, customization products, requirement analysis, rough set