ORIGINAL ARTICLE Using catastrophe theory to analyze subway fire accidents Xiaofei Lin 1,2 · Shouxin Song 1 · Huaiyuan Zhai 1 · Pengwei Yuan 3 · Mingli Chen 1 Received: 4 February 2019 / Revised: 9 October 2019 © The Society for Reliability Engineering, Quality and Operations Management (SREQOM), India and The Division of Operation and Maintenance, Lulea University of Technology, Sweden 2020 Abstract Catastrophe theory can describe a continuous process that is undergoing abrupt changes. A dynamic process can be considered to be a swallowtail catastrophe if it has the following six qualities: bimodality, divergence, sudden transitions, hysteresis, inaccessibility and irre- versibility. In this paper, the swallowtail catastrophe model is applied to describe the changing dynamic process of subway fire accidents. This dynamic process is also proved to have the six qualities of a swallowtail catastrophe. By using the swallowtail catastrophe model, we construct a model for the subway fire accidents, and we present anal- yses of subway fire accidents. On the basis of the model and analyses, the dynamic changes in the subway fire accident evolution process can be described with a novel approach. The causes of fire accidents in subways are also discussed, from the perspective of the fire triangle and four elements of an accident. We hope that this study’s theo- retical descriptions and discussion of subway fire accidents will facilitate a profound analysis of subway safety. Keywords Subway · Fire accident · Swallowtail catastrophe · Fire triangle · Fault tree analysis (FTA) 1 Introduction Subway construction in China has been rapid and prolific in recent decades. According to the research group that prepared the Annual Report on Urban Railway System in China, and to the preliminary statistics of the Urban Mass Transit Technical Committee of China Civil Engineering Society (CCES), 159 urban rail transit lines had been built and were operating in 32 cities in mainland China As of December 31, 2017. The total mileage in service was 4750 km (China Urban Rail Transit Association 2018). The data for those transit lines are shown in Table 1. With the current boom in subway system construction, however, the problem of safety also becomes more serious. Due to complex system structures, special underground airtight space structures and frequent heavy passenger flows, subways have numerous safety issues. From the early steam subways to the current electric power subways, subway accidents have happened frequently in history. Subway fire accidents have attracted the attention of many scholars, due to the severity of such accidents and the diversity of the inducing factors. The Daegu subway fire in 2003 provides an example that has been studied by many researchers. The process of handling and controlling the fire accident, the government and related organizations’ response and rescue systems, the behavior of survivors and the subway station’s mechanical system have all been investigated and analyzed (Hong 2004; Marlair et al. 2006). The fire ventilation system and smoke for the 2003 Daegu subway station fire have been simulated and ana- lyzed by using computational fluid dynamics (CFD) (Lee and Hur 2012; Choi and Hur 2013). The escape routes, and the human behaviors and psychology, were studied after the accident (Kim et al. 2004; Liang et al. 2017; Jeon et al. & Huaiyuan Zhai hyzhai@bjtu.edu.cn 1 School of Economics and Management, Beijing Jiaotong University, Beijing 100044, China 2 Civil Engineering and Agriculture School, Anhui University of Technology, Ma’anshan 243032, China 3 Business School, University of Jinan, Jinan 250022, Shandong, China 123 Int J Syst Assur Eng Manag https://doi.org/10.1007/s13198-019-00942-2