Human Reliability Analysis by Cognitive Approach for Unloading Process in an ALDS (Auto LPG Dispensing Station)

Abstract

Background/Objectives: Accident dynamics always considers the role of humans in order to ensure effective prevention of dangerous events in engineering industries where the execution of highly repetitive and standardized tasks occurs. The centrality and responsibility of the role entrusted to the human operators are exalted because it requires problem solving and decision making ability. Methods/Statistical Analysis: Human operator is the core of a cognitive process that leads to decisions, influencing the safety of the whole system in function of their reliability. The main focus of the research is to systematically predict human error potentials (Failure probability) during unloading process of LPG from truck tank to the storage tank and to determine the required safety control levels. The paper adopted CREAM (Cognitive Reliability and Error Analysis Method) basic and extended versions in order to assess human reliability and is demonstrated with the above stated operator activity. Findings: The probability value for most of the failures are included in the 'tactical'control mode range 1.2E-3<P<8E-2 (1.0E-3 < p < 1E-1), as shown by the basic version of methodology. The overall human error probability value is assigned as the maximum value of the sub-tasks which is 8E-2. Application/Improvements: Quantification of failure probability is HRA is a highly difficult task. Availability of failure data helps to take various maintenance and management decisions. Consequently, the research contributes to safety at work and prevention of human injury and loss of life.