E-Net Modeling and Analysis of Emergency Response Processes Constrained by Resources and Uncertain Durations

Time and resource management and optimization are two important challenges for an emergency response process, by which all individuals and groups manage hazards in an effort to avoid or ameliorate the impact of disasters. Compared with a traditional business process, an emergency response process has its own features. To our best knowledge, there is no formal method to model and analyze emergency response processes by taking uncertain activity execution duration, resource quantity, and resource preparation duration into account. This paper presents such a method based on an E-Net that is a Petri net-based formal model for an emergency response process constrained by resources and uncertain durations. According to the number of available resources, execution of an E-Net is classified into the worst, delayed, and best cases. Based on a priority-activity-first strategy and corresponding algorithms, this paper finds the duration to execute each activity for the delayed case. By experiments, we prove that the proposed strategy can ensure shorter execution duration of the whole process than a conventional one. A running case of a chlorine tank explosion is given to validate the proposed method.