The inherent safety intervention framework (ISIF) was developed to integrate the inherent safety level assessment methods to the process simulation tools. This framework is considered as a major breakthrough in the development of inherently safe design. In this framework, the best process route is selected by using the Process Route Index (PRI), and the inherent safety level of all process streams is estimated by using Process Stream Index (PSI). Moreover, the worst stream is identified on the basis of the highest magnitude of PSI. However, benchmarking of the worst stream is difficult to predict by using the original ISIF. In this work, a benchmarking criteria for a worst process stream is established through risk assessment. This reform could potentially improve the reliability of the original ISIF. © 2016 The Authors.