Facilitating the application of systems-theoretic process analysis in healthcare: Creating control structures using...

Systems-theoretic process analysis (STPA) is a prospective safety assessment tool increasingly applied in healthcare. A problem hampering STPA proliferation is the difficulty of modeling systems for analysis by creating control structures. In this work, a method is proposed to use existing process maps-commonly available in healthcare-when creating a control structure. The proposed method entails (1) extract information from the process map, (2) determine the modeling boundary of the control structure, (3) transfer the extracted information to the control structure, (4) add additional information to complete the control structure. Two case studies were conducted: (1) ambulance patient offloading in the emergency department and (2) ischemic stroke care with intravenous thrombolysis. The amount of process map-derived information in the control structures was quantified. On average, 68% of the information in the final control structures was derived from the process map. Additional control actions and feedback were added from nonprocess map sources for management and frontline controllers. Despite the differences between process maps and control structures, much of the information in a process map can be used when creating a control structure. The method enables the creation of a control structure from a process map to be done in a structured fashion.