## 2 Literature Review
### Failure Mode and Effect Analysis  
A failure mode and effects analysis (FMEA) focuses on identifying the nature of the damage or the cause that could lead to the failure (potential failure mode) due to the design, manufacture, or service. After that, the impact of the expected damage (effects analysis) will be analyzed, and finally, a way is found to prevent the expected damage (problems prevention) [47]. Using FMEA principles to analyze and solve the root of real problems in the process (design, manufacture, or service) will give manufacturers a more comprehensive perspective on problem solving, which will reduce repetitive problems and thus result in reduced variations in the manufacturing process [48]. Therefore, every product is of consistent quality and meets the required standards. During an FMEA, risks are prioritized based on predefined criteria, and actions are then taken to address the higher-priority failure modes first [49].  
The FMEA technique was developed for aerospace, vehicle, and military applications in the 1950s and was initially known as the failure mode effects and criticality analysis (FMEA); later in the 1960s it was applied to reliability engineering [50]. The FMEA technique is a widely used method for engineering risk analysis aimed at identifying possible defects and predicting their consequences. It was developed and applied to assess the risk of defect characteristics in design, process, and quality management, and it is a popular tool in these areas [51]. A risk analysis using the FMEA technique prioritizes the risk of the critical failure characteristics (potential failure mode) under the risk priority number (RPN) obtained from the three criteria assessments: severity: S, occurrence: O, and detectability: D; this is calculated as PRN = S \(\times\) O \(\times\) D [52]. To evaluate the severity, occurrence, and detectability of each failure mode, a 10-point scale is used. Failure modes with higher RPN values are considered more critical and given higher priority than those with lower RPN values [52; 53]. While FMEA techniques are widely used across various industries to assess the risks of failure modes, multiple expert opinions can result in vague and imprecise risk evaluations, leading to conflicting evidence that can be challenging to manage. As business situations become more complex with uncertainties and service process characteristics, FMEA applications are continuously evolving and becoming more advanced [54].  
FMEA has been applied in many other industries and is widely used by many companies worldwide to develop new designs and technologies and analyze and plan the quality of production processes and products. An FMEA has been used in previous studies to assess service quality and enhance the quality of services provided in the airline industry [15; 55; 56]. [PERSON] et al. [57] applied an FMEA in the healthcare industry to improve medication safety in the medication use process. The authors used an FMEA to analyze both existing systems and new policies to identify potential errors in the system. [PERSON] and [PERSON] [58] applied an FMEA in the construction industry in the Russian Federation and demonstrated its potential application to ecological issues. Applying the FMEA methodology in ecology enables developers to evaluate the risks and potential damages resulting from inconsistencies in design and technological processes at the early stages of product development. [PERSON] et al. [59] proposed a method for enhancing the service quality of logistics centers by integrating an FMEA with [PERSON]'s model. The approach allows for the identification of potential failures and their consequences as well as the evaluation of customers' satisfaction and dissatisfaction with logistics center services.