# Risk Assessment of Lift-Jacking Accidents Using FFTA-FMEA
## 2 Literature Review  
### Lift Risk Research Review  
At present, scholars' research on lift accident risk assessment is broadly divided into qualitative analysis, quantitative analysis, and combined qualitative and quantitative analysis methods. In the area of qualitative analysis, numerous scholars have traced the causes of lift accidents in depth by accident analysis, literature mining, the Delphi method, or using FTA. [PERSON] and [PERSON] studied a large number of accident investigation reports and applied the FTA method to define the unsafe status of lift equipment and achieved an accurate analysis of accident causes [3]. [PERSON] selected a variety of accident cases in recent years and used the \"2-4\" model to classify and analyze the direct causes, indirect causes, root causes, and root causes of lift accidents [4]. All the above scholars analyzed the causal factors of lift accidents from a single perspective, but it is impossible to assess the magnitude of risk by considering only from a qualitative perspective, so some scholars have used quantitative analysis to study the risk of lift accidents. [PERSON] used the component hazard evaluation method of PHA-FMEA to refine the risk level corresponding to each component in different states and successfully constructed the lift safety evaluation index system [5]. [PERSON] used a fuzzy comprehensive evaluation method to assess the risk of lift systems and established corresponding risk evaluation level classification guidelines [6]. In recent years, a combination of qualitative and quantitative analysis of lift accidents has become popular among scholars. This method can quickly trace the key causes of lift accidents and also quantify lift risks in a comprehensive manner to build a lift system risk assessment system. [PERSON] proposed a fault tree for lift systems based on expert knowledge and multi-source data and used TOPSIS Methodology to achieve the optimal sequence of lift vibration faults [7]. [PERSON] applied the CW-VIKOR method to summarise the types of lift faults, to build a highly relevant lift operation assessment system, and to determine the safety assessment level of lift operation [8].  
It is apparent that scholars have devoted significant efforts to researching lift accidents, with a prevailing trend towards employing a combination of qualitative and quantitative methodologies. However, the current research approach has not yet reached a state of maturation. Specifically, in the construction of accident causation assessment models, the reliance on the subjective expert judgement has led to the identification of ambiguous and uncertain causal factors, with varying levels of expertise amongst different practitioners. As a result, the analysis results exhibit a lack of objectivity and accuracy. Additionally, most of the existing research has only identified key causal factors, with an incomplete depiction of the actual level of risk. Such findings can result in managers developing a one-sided perception of risk. Moreover, lift accidents are typically analyzed in a homogenous manner, without differentiation into specific accident categories, rendering the conclusions of such analysis general in nature, but lacking in pertinence. Notably, despite being one of the top five lift accidents, lift-jacking accidents have received little attention from academics, and thus, they deserve further investigation.