Journal of the Ergonomics Society of Korea Vol. 32, No. 6 pp.535-540, December 2013 http://dx.doi.org/10.5143/JESK.2013.32.6.535 A Study on the Performance of Causal Links between Error Causes: Application to Railroad Accident Cases Dong San Kim 1 , Wan Chul Yoon 2 1 KAERI, Integrated Safety Assessment Division, 989-111 Daedeok-daero, Yuseong-gu, Daejeon, 305-353 2 KAIST, Department of Knowledge Service Engineering, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701 ABSTRACT Objective: The aim of this study is to evaluate the effectiveness and efficiency of causal links between various error causes in human error analysis. Background: As finding root causes of human error in safety-critical systems is often a cognitively demanding and time-consuming task, it is particularly necessary to develop a method for improving both the quality and efficiency of the task. Although a few methods such as CREAM have suggested causal linking between error causes as a means to enhance the quality and efficiency of human error analysis, no published research to date has evaluated the performance of the causal links. Method: The performance of the CREAM links between error causes were evaluated with 80 railway accident investigation reports from the UK. From each report, errorneous actions of operators were derived, and for each error, candidate causes were found by following the predefined links. Two measures, coverage and selectivity, were used to evaluate the effectiveness and efficiency of the links, respectively. Results: On average, 96% of error causes actually included in the accident reports were found by following the causal links, and among the total of 121 possible error causes, the number of error causes to be examined further was reduced to one-tenth on average. As an additional result of this work, frequent error causes and frequently used links are provided. Conclusion: This result implies that the predefined causal links between error causes can significantly reduce the time and effort required to find the multiple levels of error causes and their causal relations without losing the quality of the results. Application: The CREAM links can be applied to human error analysis in any industry with minor modifications. Keywords: Human error, Human error analysis, Causal factor, Performance shaping factor(PSF), CREAM 1. Introduction 원자력, 항공, 철도, 의료 분야와 같이 ' 안전' 이 특히 중요 시되는 산업에서 대형 사고의 주된 원인으로 여겨지는 인적 오류(human error)의 원인을 제대로 분석하는 일은 인지적 으로 복잡하고 시간과 인력이 많이 필요한 일이지만, 현업에 서는 시간, 인력, 인간공학 분야 전문성 부족 등의 제약으로 인해 피상적 수준의 원인만 파악하는 경우가 많은 것이 현실 이다. 따라서 인적오류 분석의 질과 효율성을 모두 개선할 수 있는 방법의 개발이 요구된다. 그 동안 많은 인적오류 분석 방법(Human Factors Analysis and Classification System (Wiegmann and Shappell, 2003), Human Performance Enhancement System(INPO, 1990 등)들이 개발되어 왔 지만, 많으면 100개가 넘는 인적오류의 원인요소들을 리스 트로 제공할 뿐, 그 중에서 적절한 원인요소를 찾고 해당 원 Corresponding Author: Wan Chul Yoon. KAIST, Department of Knowledge Service Engineering, 291 Daehak-ro, Yuseong-gu, Daejeon, 305-701. Phone: +82-42-350-3119, E-mail: wcyoon@gmail.com Copyright@2013 by Ergonomics Society of Korea(pISSN:1229-1684 eISSN:2093-8462). All right reserved. ○ cc This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License(http://creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. http://www.esk.or.kr