This paper proposes the use of Probabilistic Relational Models (PRM) for analyzing dependencies between Information Security Governance (ISG) components and its impact on process capability of mitigating information security vulnerabilities. Using the PRM enables inference between different ISG components expressed in probabilities, and also inference on the process capability. A concrete PRM which exemplifies how to assess the capability of the access control process is further presented, and thus showing how the PRM can be adapted to fit the analysis of a specific process in an organizational environment.