TY - GEN
T1 - Automated Markov analysis on safety systems to evaluate the reliability
AU - Bliek, van den, E.G.
AU - Spiker, R.Th.E.
AU - Rouvroye, J.L.
AU - Brombacher, A.C.
PY - 1999
Y1 - 1999
N2 - To reduce the inherent risk of industrial processes to an acceptable level, a safety instrumented system (SIS) can be added to the process. The main function of this system is to intervene when the process runs out of control. This intervention consists of taking the process back to a safe state, often a shutdown of the process. A safety instrumented system generally consists of sensors, a logic solver and actuators. To determine the risk of the process, the safety and reliability of the safety instrumented system have to be analysed. This analysis has to comply with several standards, of which the IEC61508 standard is the most recent and, by many people also considered most relevant, standard. One of the results of a safety analysis in accordance with IEC61508, is the safety integrity level (SIL) of the system. As defined by this standard the SIL indicates the average probability that the safety instrumented system will not perform its safety function on demand. As proven by Rouvroye et al. (1996) enhanced Markov analysis is currently the most comprehensive analysis method available to calculate the SIL. This analysis method has a scientifically sound basis, but also has some practical drawbacks. The analysis can become quite time-consuming and complex. One way to overcome these drawbacks is an automated software tool. A prototype of such a tool has been developed and is called A-MASTER: Automated Markov Analysis on Safety systems to Evaluate the Reliability. The paper explains several development aspects of such an automated software tool and the principles which underlie A-MASTER and its main functionality. It also gives a practical application of the tool
AB - To reduce the inherent risk of industrial processes to an acceptable level, a safety instrumented system (SIS) can be added to the process. The main function of this system is to intervene when the process runs out of control. This intervention consists of taking the process back to a safe state, often a shutdown of the process. A safety instrumented system generally consists of sensors, a logic solver and actuators. To determine the risk of the process, the safety and reliability of the safety instrumented system have to be analysed. This analysis has to comply with several standards, of which the IEC61508 standard is the most recent and, by many people also considered most relevant, standard. One of the results of a safety analysis in accordance with IEC61508, is the safety integrity level (SIL) of the system. As defined by this standard the SIL indicates the average probability that the safety instrumented system will not perform its safety function on demand. As proven by Rouvroye et al. (1996) enhanced Markov analysis is currently the most comprehensive analysis method available to calculate the SIL. This analysis method has a scientifically sound basis, but also has some practical drawbacks. The analysis can become quite time-consuming and complex. One way to overcome these drawbacks is an automated software tool. A prototype of such a tool has been developed and is called A-MASTER: Automated Markov Analysis on Safety systems to Evaluate the Reliability. The paper explains several development aspects of such an automated software tool and the principles which underlie A-MASTER and its main functionality. It also gives a practical application of the tool
M3 - Conference contribution
SN - 1-556-17708-9
T3 - Technical papers of ISA
SP - 117
EP - 126
BT - Compliance, safety and environmental advances : technology update LIV ; 5-7 October 1999, Philadelphia, Pennsylvania, USA ; international conference and exposition for advancing measurement, control and automation technologies, products and services / Ed. K. Konrad
PB - Instrument Society of America
CY - Research Triangle Park, NC
ER -