Inherent safety indices have been suggested to choose between alternative process and chemical reaction routes in conceptual chemical process design. The indices are relative ranking methods that add up parameters without considering the difference in the magnitude of the hazard, complexity of the procedure, or expert opinion. We propose an improved framework based on fuzzy logic using chemical properties, process data, and chemical accident databases. The proposed methodology is applied to the methyl methacrylate (MMA) process as a case study. The results are compared with existing methods and experts' rankings by using three risk-rules, which are related to the experts' opinions and the tendency of decision makers. The risk-standard rule showed same results to that of the expert's scoring, while the ranking results are slightly different based on risk-easy and risk-hard rules. This methodology can facilitate the ranking of alternatives for decision making in the preliminary design stage.