“…Some identified and analysed criteria for enhancing the quality of maintenance activities. Reference [80] proposed an equation to evaluate the amount of unreadable sentences in aircraft maintenance technical orders since their readability can affect the quality and reliability of aircraft maintenance. Reference [81] proposed a performance evaluation model for aircraft maintenance staff, exploring the weights of different evaluation criteria (Basic Knowledge, Aircraft Maintenance Workload, Other Workload, Self-Development, Problem-Solving Skill, Problem-Solving Attitude, Responsibility, Teamwork, Work Quality, Reliability, and Attendance Rate), whereas Reference [83] proposed a competence measurement tool to assess the competency of maintenance employees, instead research modelling of plant operators' maintenance proficiency was addressed by Reference [84] to provide a classification tool to assist managers to select the best operative.…”