A framework presented addresses the three main parts of a process hazards analysis study: hazard identification, hazard evaluation, and hazard mitigation. The framework utilizes a hybrid methodology that effectively combines a qualitative digraph model-based technique for performing hazard identification and a quantitative optimization-based technique for performing hazard evaluation and hazard mitigation. The combined framework circumvents the local minima problems faced by mathematical optimization algorithms, as well as the qualitative ambiguities that plague digraph models. The systems used to implement the framework are BatchHAZOPExpert, gPROMS, and gOPT. BatchHAZOPExpert is used for hazard identification, while gPROMS and gOPT are used for hazard evaluation and hazard mitigation. The application of the integrated framework is illustrated by implementing it on two industrial case studies.