On the use of penalty approach for design and analysis of univariate alarm systems

Alarm systems indicate abnormal conditions of the underlined plant equipment enabling operators to take corrective actions, and bring the equipment back to its normal condition. This paper presents a new approach for designing a generalized delay timer based on the penalty scenario and Markov chain schemes. The penalty approach is an extension for the well-known “n-sample on/off delay timer” approach in designing alarm systems. Three performance indices named, False Alarm Rate (FAR), Missed Alarm Rate (MAR) and Average Alarm Delay (AAD) are derived for the proposed penalty approach using Markov theory. Also, a new index named “Mean Time to Alarm (MTTA)” is introduced to analyze the underline alarm system, and to compute AAD. Finally, the effectiveness of the proposed method is investigated and compared with that of the other methods through a case study.