SOL - ایمنی از طریق یادگیری سازمانی: روشی برای تجزیه و تحلیل رویداد

Under the guidance of Bernhard Wilpert† a research group at the Berlin University of Technology developed an event analysis methodology called safety through organizational learning (SOL). The method has been adopted by the Swiss and German nuclear industries as standard procedure for their in-depth event analyses. SOL aims at facilitating organizational learning from events by supporting the process of analyzing events, ensuring its standardized conduct and mobilizing expert knowledge and creativity in the analysis. In this paper we provide a short description of SOL and its theoretical background. We summarize the empirical evidence and practical experience regarding SOL, which proves it to be a valid methodology that gives sufficient support to analysts. Finally, practical experiences and challenges for future research are discussed.

Nearly 20 years ago the influence of human factors on incidents in German nuclear power plants became a topic of increasing interest and significance. At this time practitioners from the nuclear power industry understood human factors mainly as human errors at the man–machine interface, whereas safety researchers had a quite different understanding that subsumed organizational and environmental aspects under the term human factors (e.g. Reason, 1990). In 1992 a research group at Berlin University of Technology started under the guidance of Bernhard Wilpert with the development of a new event analysis methodology called safety through organizational learning (SOL). The authors of the present article worked in this research group. Bernhard Wilpert’s central idea was to propagate a holistic socio-technical system approach for analysing events which implies that human factors do not only relate to the immediate man–machine interface, but comprise human actions on all system levels in as much as they contribute to the critical outcome of safety. According to the organizational learning literature (e.g. Argyris and Schoen, 1978), one important goal of event analysis is to draw lessons from an event to prevent future events. Therefore, adequate recommendations and safety measures must be implemented for all contributing factors identified. When the research group started the development of SOL, event reports in nuclear industries discussed technical failures and human errors as the main contributors to events. Organizational or inter-organizational factors were only considered on an informal basis and did not get due weight in the lessons learned. The group speculated about potential reasons and came to the conclusion that event analysts might not have adequate knowledge about organizational factors, and therefore their methods did not explicitly cover these factors. Moreover, the strong focus on apparent factors might result from shortcomings in causal reasoning. Consequently, the development of SOL should fulfill the following requirements: • it should cover a broad range of human, organizational, and inter-organizational factors derived from theory and empirical data; • it should be easy to use without expert knowledge in human factors psychology, because it should be applied by operators and supervisors in nuclear power plants; • it should help to overcome well known shortcomings in human causal reasoning which could lead to truncated search in event analysis; • it should support organizational learning from events; • it should have empirical validation. In the following sections we will describe the development of the method, show how SOL was evaluated and close with open questions and challenges for the future. 2. The development of SOL – safety through organizational learning SOL was initially developed for the nuclear power industry (Becker et al., 1995 and Wilpert et al., 1997). However, a version for the chemical industry exists (Wilpert et al., 1998) and a computer supported version was developed as well (Maimer et al., 1999). At the time SOL was developed, event analyses were still dominated by approaches characterized by attributions of fault to individual or/and technical actors (Benner, 1981a, Benner, 1981b, Hendrick and Benner, 1987, Manuele, 1982 and Shealy, 1979). Nevertheless, in high hazard industries a trend of systematic analyses supported by different methodologies could be observed (Fahlbruch and Wilpert, 1999). Unfortunately some of those methodologies were not completely published (e.g. the German human-factor concept of Vereinigung der Großkraftwerksbetreiber – VGB and the Human Performance Enhancement System of INPO – Institute of Nuclear Power Operations). For the development of SOL we reviewed the following methodologies: • ASSET – Assessment of Safety Significant Events Teams (IAEA, 1991 and IAEA, 1994); • Change Analysis (Bullock, 1981); • HPES – Human Performance Enhancement System (INPO Bishop and LaRhette, 1988); • MORT – Management Oversight and Risk Tree (Johnson, 1973 and Johnson, 1980); • STEP – Sequentially Timed Event Plotting (Hendrick and Benner, 1987); • TOR – Technique of Operations and Review (Weaver, 1973). The above methodologies are based on different accident causation models, e.g. Change Analysis and HPES had no explicit model, whereas MORT and STEP were based on explicitly formulated models. The methodologies vary in degree of standardization from general requirements for the process (Change Analysis) up to a set of attributes evaluated as adequate or less than adequate (MORT). Although ASSET, MORT and TOR explicitly consider organizational factors, inter-organizational factors are not included in any of the reviewed methods. None of the methods had explicit features for overcoming judgmental biases or shortcomings in causal reasoning.

SOL facilitates organizational learning from events by supporting the process of analyzing events, ensuring its standardized conduct and mobilizing expert knowledge and creativity of the analysis (Becker et al., 1995, Fahlbruch et al., 1998, Miller et al., 1999 and Wilpert et al., 1997). The method helps to avoid generally known biasing tendencies when events are analyzed. Based in sound socio-technical systems theory, the method guarantees a comprehensive analytic scope with contributing factors from a wide range of possible sub-systems of the focal organization. Ideally, analyzing events with SOL fosters an attitude of critical reflection on system performance in the whole organization. Due to Bernhard Wilpert’s vision and drive, SOL is a product of interdisciplinary work and has been adopted by the Swiss and German nuclear power industries as the standard procedure for their in-depth event analyses. The main challenges for future refinement of SOL refer to the aggregation of “lessons learned” from an event and the handling of cultural factors that emerge in the course of an event analysis.