A study of the contribution of human factors to human-machine system failures in dynamic mission operations

The accident causation model used by the U.S. Navy and Marine Corps in aircraft mishap investigations is in transition to the Department of Defense Human Factors and Analysis and Classification System (DoD HFACS) -- based largely on the HFACS developed by Wiegmann and Shappell (2003) and the "Swiss Cheese" model of accident causation introduced by James Reason (1990) in the early 1990s.This dissertation employed the taxonomy of human factors presented in the DoD HFACS model to analyze and compare the human causes resident in failures of single- and multiple-operator human-machine systems functioning in a dynamic, mission-oriented environment. Specifically, the human factors involved in flight-related mishaps generated by single-piloted and multi-crewed U.S. Navy and Marine Corps tactical jet aviation platforms between fiscal years 1997 and 2007 were examined. The method applied to this study began with the construction of a previously undeveloped data set containing the mishap human causal factors cataloged in accordance with the DoD HFACS followed by a quantitative evaluation of this data set to determine the mean mishap rate and human causal factor occurrence (by number and type) between the two system configurations. In all, data from 497 total mishap reports were evaluated resulting in 1,421 total human factors analyzed.The results of this investigation revealed a generally higher overall mean failure rate in the multiple-operator human-machine system. However, when the data was sorted by failure severity, the failure rates in the most severe (Class A) mishaps were nearly identical between the two systems, while failure rates in the least severe (Class C) mishaps diverged and were significantly higher for the multiple-operator system. The second analysis in this study examined the mean number of factors resident in each mishap (factor occurrence rate) and revealed a generally higher overall mean in the single-operator system than the multiple-operator system. Evaluation of the data, sorted by failure severity in this case, revealed a similar mean between the two systems in Class C mishaps and a greater distinction between the two systems in Class A mishaps. The final analysis of the data explored differences in the types of factors produced by each system and showed Cognitive Factors, Decision Errors, and Communication, Coordination, and Planning to be the most common for both system configurations. Overall, the single-operator system incurred significantly higher Cognitive Factors, Adverse Physiological State factors, and Skill-Based Errors while the multiple-operator system incurred higher Resource Management (Organizational Influences) causes. Further, while the difference in the failure rate between the two systems was more apparent in Class C mishaps, the distinction between both the number and types of factors generated by each system was more apparent in Class A mishaps.The human-machine system failures generated by the eight aircraft models and their crews in the 11 years of data captured in this study cost...