Dissonance between multiple alerting systems.II. avoidance and mitigation

For pt.I. see ibid., p. 366-75. The potential for conflicting information to be transmitted by different automated alerting systems is growing as these systems become more pervasive in process operations. Newly introduced alerting systems must be carefully designed to minimize the potential for and impact of alerting conflicts. A model of alert dissonance, developed in a companion paper (Part I), provides both a theoretical foundation for understanding conflicts and a practical basis from which specific problems can be addressed. Alerting systems are hybrid processes, involving continuous process dynamics and discrete alert level changes in state space. This paper presents a hybrid model to facilitate analysis of dissonance. Using backward reachability analysis, regions of dangerous dissonance space are identified. Then, modifications can be made to the control strategy of the process or to the alerting thresholds to avoid dangerous consequences of dissonance. An example problem is presented to demonstrate the application of the hybrid model to identify dangerous dissonance space and to identify proper actions to avoid dangerous consequences of dissonance.