中文摘要：

当前,软件需求优化的研究多集中在提高需求的完整性、设定需求的优先级以及消除需求的歧义性等方面。从需求优先级设定入手来进行需求优化,首先从系统的整体性和需求的层次性出发,提出以解释结构模型（interpretative structural model,ISM）和层次分析（analytical hierarchy process,AHP）法相结合的需求优先级排序方法。其中,ISM对需求进行结构优化和分层处理,然后对最上层的需求使用AHP进行需求优先级排序,并将该方法命名为结构层次分析（structural analytical hierarchy process,SAHP）,接着通过与AHP的比较,说明性能总体上好于后者,最后通过进度和成本约束,表明该方法能够判断项目进度和成本的合理性,降低因需求导致项目失败的风险。

英文摘要：

Many research hotspots of current software requirements are widely noted,for example： improving the completeness of requirements,setting the priority of requirements and eliminating ambiguity the requirements,which is requirements optimization in essence.The method of prioritizing requirements based on the combination of interpretative structural model（ISM） and analytical hierarchy process（AHP） is proposed,called structural analytical hierarchy process（SAHP）.First,the hierarchical model of software requirements is built with ISM.Next,the requirements of top level of the model are prioritized by analytical hierarchy process.Then,the case analysis is given,and the strengths and weaknesses of AHP and the method are compared.The results show that SAHP is better than AHP as s whole.Finally,this method is distinguished with the schedule and cost analysis if the schedule and cost of the project are rational,and can reduce the failure probability of the project.