Designing of a Univariate Alarm System based on Delay Timers Using Multiple Thresholds

Alarm systems play an important role in ensuring safe and efficient operations. Delay timer as a simple method has effective role in managing alarms and reducing nuisance alarms. In this paper, a new delay timer is introduced based on multi levels of thresholds. This scenario named as multi-levels delay timers. In this scenario, the regions of upper and lower areas of threshold are divided to some regions by considering new thresholds with various delays. In this paper, three performance indices named, False Alarm Rate (FAR), Missed Alarm Rate (MAR) and Average Alarm Delay (AAD) are derived for multi thresholds approaches using Markov models. Also, the new index named “mean time to alarm (MTTA)” is introduced to analysis alarm system and computation of AAD in proposed scenario. The performance of the proposed method and other methods for designing of delay timers are compared and the effectiveness of proposed method is provided during some case studies.