Human Error Probability Values Research Articles

Identification of Operator Reliability on Sewing Department According to Task Analysis

PT. XYZ is one of the textile companies that produces garments exported to some countries . The company has identified Sewing Department has an error rate above the target at around 1.5%. Similar models were worked Line A1 and A7 has a productivity rate is only 77.14% (below the company's target percentage of 80% ) . This study aimed to identify reliability sewing operator so it can be used as a basis for identifying an increase in productivity of the operator at the Department of Sewing at PT. XYZ . This research method using human reliability (Human Reliability Assessment) is based on the task analysis that method Technique for Human Error Rate Prediction (THERP), Method of Human Error Assessment and Reduction Technique (HEART) and the method of Standardized Plant Analysis Risk Human Reliability Assessment (SPAR-H) to measure the reliability of the operator in the task. Fault Tree Analysis (FTA) is used as a technique to analyze the causal relationship of a risk assessment and measurement reliability. Rework type on Line A1 there are 6 tasks and Line A7 there are 5 task . From analysis to Human Error Probability (HEP) on Fault Tree turns HEART method has the highest value compared to SPAR-H and THERP methods. HEP analysis using HEART method s on Line A1 of 0.319 while the Line A7 of 0.399. Potential reworks using SPAR-H Method on Line A1 and A7 is the task 4 with a HEP value on Line A1 of 0.00959 and Line A7 of 0.00209 . HEP analysis using THERP Method for Line A1 of 0.1615 while the Line of 0.2001. Sewing operator reliability in identifying an increase in labor productivity on Line A1 and A7 looks at HEP value for each task performed. On Line A1 and A7 seen that the HEP is below 0.5 means the reliability of operators in doing the task can be improved with the cooperation of all the company components .

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

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.

An integrated method for human error probability assessment during the maintenance of offshore facilities

The paper presents a novel approach for Human Error Probability (HEP) assessment by integrating the Success Likelihood Index Method (SLIM) with the Technique of Human Error Rate Prediction (THERP). In this approach, the SLIM has been embedded within the THERP framework to generate the nominal HEP data when it is unavailable. The developed methodology is implemented to an offshore condensate pump maintenance task. In the first step of this study, the human error was estimated considering all the standard tools and procedures which are in place. In the second step, as an additional measures, radio frequency identification (RFID) based tools are utilized and HEP is recalculated. Without the application of RFID tools, the HEP value is found to be 5.7244×1022 or estimated as 5.72% with an uncertainty bound of 1.1448×10−2–1.1452×10−1. With RFID tools, it is reduced to 4.6342×10−2 or 4.63%, with an uncertainty bound of 2.145×10−2–2.089×10−1 which yields a net HEP reduction of 1.09%.

Modeling of a Dependence between Human Operators in Advanced Main Control Rooms

For the human reliability analysis of main control room (MCR) operations, not only parameters such as the given situation and capability of the operators but also the dependence between the actions of the operators should be considered because MCR operations are team operations. The dependence between operators might be more prevalent in an advanced MCR in which operators share the same information using a computerized monitoring system or a computerized procedure system. Therefore, this work focused on the computerized operation environment of advanced MCRs and proposed a model to consider the dependence representing the recovery possibility of an operator error by another operator. The proposed model estimates human error probability values by considering adjustment values for a situation and dependence values for operators during the same operation using independent event trees. This work can be used to quantitatively calculate a more reliable operation failure probability for an advanced MCR.

Conservatism of the Accident Sequence Evaluation Program HRA Procedure

This paper presents a limited assessment of the conservatism of the Accident Sequence Evaluation Program (ASEP) human reliability analysis (HRA) procedure described in NUREG/CR‐4772. The data for this study are derived from simulator examination reports from the NRC requalification examination cycle for nuclear power plant operators. The ASEP procedure was used to estimate human error probability (HEP) values for critical tasks, and the HEP results were compared with the failure rates observed in the examinations. The ASEP procedure was applied by PNNL operator license examiners who supplemented the limited information in the examination reports with expert judgment based upon their extensive simulator examination experience. Comparison of the average of the ASEP HEP values with the fraction of the population actually failed and demonstrated that the ASEP HEP values are larger (conservative) by a statistically significant average factor of two. Partitioning of tasks into subgroups based on the ASEP HEP values and comparison of the subgroup average ASEP HEP values with observed subgroup failure rates showed little or no conservatism for small ASEP HEP values, but considerable conservatism for larger ASEP HEP values.