# Risk Factor Analysis of Elevator Brake Failure Based on DEMATEL-ISM
## 1 Introduction  
As a critical component of vertical transportation in buildings, elevators are indispensable electromechanical devices, especially in modern high-rise buildings. They bring convenience to us and improves our working efficiency and living standards [1]. With the rapid urbanization in China, elevator ownership has surged significantly [2]. At the same time, the number of aging elevators is increasing annually, leading to a rise in frequent malfunctions and, consequently, a notable increase in accidents with casualties [3]. Currently, a multitude of factors contribute to elevator accidents, and these factors are intricately interconnected. The task of detecting all potential faults during routine elevator maintenance is challenging, thereby potentially elevating the risk of elevator accidents. Furthermore, the current advancement in elevator monitoring systems primarily focuses on predicting faults by monitoring extensive individual datasets. However, these systems often overlook the interdependencies among various faults, rendering it difficult for them to comprehensively analyze all contributing fault factors. The elevator braking system serves a vital role in ensuring the safe operation of elevators [4]. The control and safety functions of elevators are ultimately reliant on the brake system [5; 6]. Once the safety function of the brake fails, it often leads to such serious accidents as falling, roofing, and shearing of the elevator car, which brings unacceptable risks and great threats to passengers' lives and property [7; 8]. Elevator brake failure is a leading cause of elevator accidents [9]. For this reason, the State Administration for Market Regulation has launched a national elevator brake hidden trouble special investigation and management work. Aiming at the problems of high failure rate, large failure hazards, and serious accident hazards of elevator brakes, it is of great significance to explore the risk factors of elevator brake failure and control them to improve the level of elevator safety governance. Brake failure modes are complex and varied, with research into these failures being essential for understanding risks [10]. Brake failure has the characteristics of mixed, correlation and unknown [11]. At present, many scholars have studied and analyzed brake failures from different perspectives. [PERSON] [12] proposed several typical failure forms, failure consequences, and failure causes of elevator brakes, and put forward modification suggestions for the current standard. Some scholars [13; 14] analyze the brake failure of elevators based on a variety of failure conditions and study the prevention and control measures of brake failure. Some scholars [15; 16; 17; 18; 19; 20] analyze the causes of elevator brake failure through simulation technology, theoretical calculations, test methods and so on. However, the existing research mainly focuses on the causes of brake failure, life prediction, etc., and lacks a deep and systematic research on the relationship between the risk factors of elevator brake failure. This paper employs Failure Mode and Effects Analysis (FMEA) to examine the structural characteristics of elevator brakes and identify equipment failure risk factors. Based on the accident prevention theory model (24 Model), this paper provides comprehensive internal and external causes to determine the brake failure risk factors of elevators. An affiliation function is used to build the failure risk factor indicator system, and Decision-making Trial and Evaluation Laboratory (DEMATEL), and Interpretative Structural Modeling (ISM) method are applied to study the hierarchical structure and internal relationship between the factors. Finally, based on the research results, several suggestions are proposed to mitigate the risk of elevator brake failures, offering a theoretical foundation for preventing and controlling elevator drum brake accidents.