Abstract: Food safety concerns the national economy and the people’s livelihood. It is a major issue to be paid close attention by whole society. To effectively monitor the hazard levels in food supply chain, a directed graph model with Social Network Analysis（SNA） is built. Based on the k-step reachable matrix, the concepts and calculating methods of k-step observability and k-step controllability of network nodes are presented. Then, this paper composes the approach to analyze and select the critical control points with the comprehensive observability and controllability of nodes are constructed. And the influences of parameter setting on the convergence of the algorithm and the number of selected critical control points are discussed. Above works provide a necessary technical support to the food safety supervision department for implement HACCP in the food supply chains.

Key words: social network analysis, food safety, food supply chain, Hazard Analysis and Critical Control Points（HACCP）, critical control points

摘要： 食品安全关乎国计民生，是全社会普遍关注的重大问题。为了有效监控食品供应链中有害物的水平，提出基于有向图的食品供应链的社会网络分析模型。基于[k]步可达矩阵，提出食品节点的[k]步可观度和[k]步可控度的概念和测算方法。进而构建了基于综合可观可控度的关键控制点的分析与选择的方法，并对算法参数的设置对算法的收敛性和关键控制点的数量的影响进行了讨论。以上工作为食品安全监管部门在供应链范围内推行HACCP提供了必要的技术支持。

关键词: 社会网络分析, 食品安全, 食品供应链, 有害分析与关键点控制（HACCP）, 关键控制点