Resilient alarm logic design for process networks

A novel alarm-system design strategy, which takes full advantage of the inh erent hardware and spatial redundancy in a process network, is proposed in this paper. Specifically, systematic procedures have been developed to iden tify independent methods for evaluating any alarm variable in the process a nd to synthesize corresponding alarm generation logic. To implement this lo gic, the error models in data reconciliation and the formulas for evaluatin g conditional probabilities of type I and II mistakes have also been derive d. The results of applying the proposed approach to the application example show that it is indeed superior to any of the existing design techniques. This is because the resulting alarm system is appropriately tailored to min imize the expected loss. More importantly, it is resilient in the sense tha t the system performs satisfactorily even under the influence of various se nsor malfunctions.