This paper focuses on the concept of supply chain (SC) vulnerability and how to assess it. In the context of an action research project, we conducted an SC vulnerability analysis for an automotive manufacturer. Our goal is to help SC managers prevent risks and SC disruptions, which in turn can improve the robustness of the SC. We propose a number of categories of vulnerability, which are drawn from both the literature and from practice. Using a specific SC case, we present the steps of our assessment approach and discuss the different categories used, how to assess them and how to assess overall SC vulnerability.