Paths between latent and active errors: Analysis of 407 railway accidents/incidents' causes in China

The effectiveness and the safety of railway operations depend on many factors and latent errors pose the greatest risk to system safety. The Human Factors Analysis and Classification System (HFACS) has been widely used as an analytical framework for the investigation of the role of human errors in railway accidents/incidents; however, relatively few published studies with empirical evidence formally describe the independences between human factors by HFACS. Meanwhile, the occurrence frequencies of human factors and their main norms should be estimated with a large number of accidents/incidents data according to various professions and accidents. We collect and filter 407 railway accident/incident reports in China between the year of 2003 and 2014 using the HFACS framework. The results show that the four errors with the largest percentage of occurrence in the railway system are 'organization process', 'inadequate supervision', 'personal readiness' and 'skill-based errors'. Several interesting relationships and the pattern of the 'paths between categories' at the four levels in HFACS are explored by this analysis for preventing or reducing the number of human errors. The methodology is useful in presenting how a railway accident/incident or near miss occurs and revealing significant interdependences between human factors. This study highlights a way for the rail industry to look more closely at latent factors at the supervisory and organizational levels when investigating active errors of the accidents.