## 3 Results
#### 3.1.1 Estimation of Reliability Parameters
This suggests the need for frequent maintenance  
Figure 13: Evolution of reliability: (**a**) 40% reliability of Komatsu WA470 front loader bucket knife after 63 days of operation; (**b**) 80% reliability of Komatsu WA470 front loader bucket knife after 27 days of operation; (**c**) 40% reliability of the Komatsu HB365 excavator bucket tooth after 1752 h of operation; (**d**) 80% reliability of the Komatsu HB365 excavator bucket tooth after 480 h of operation; (**e**) 40% reliability of the sorting station trough after 182 days of operation; (**f**) 80% reliability of the sorting station trough after 105 days of operation. interventions or knife replacements to avoid unplanned production interruptions. A detailed analysis of the causes leading to this low reliability and a preventive maintenance plan based on this data are necessary. The reliability data reveal a concerning rate of degradation for the Komatsu WA470 front loader bucket knife. This emphasizes the need for diligent monitoring, proactive maintenance, and careful operational analysis to ensure optimal performance and minimize disruptions. Studying the evolution of reliability, it is observed that the probability that the Komatsu HB365 excavator bucket tooth will fail after 1752 h of operation is approximately 40% (Figure 13c), and to obtain an acceptable reliability of 80% (Figure 13d), the operating time decreases to 480 h of operation. The reliability degradation rate is approximately 0.0314% per hour. This gives us a quantitative measure of how quickly the tooth's reliability is decreasing. The wide confidence interval observed for the excavator tooth's reliability at 480 h (Figure 13c,d) indicates significant variability in its operating duration. This is likely due to the abrasive nature of the processed material in the Patars quarry, which can lead to unpredictable wear patterns and component failure. A reliability of 40% after 1752 operating hours shows that there is only a 40% probability of the excavator tooth functioning without defects. Therefore, there is a 60% probability of the tooth failing within this time period. A 40% reliability after 1752 h indicates significant wear or a predisposition to failures of the tooth under the operating conditions of the Patars quarry. This suggests that maintenance interventions or replacements are necessary to prevent unplanned production interruptions. The provided reliability data underscores the importance of proactive maintenance and monitoring of the Komatsu HB365 excavator bucket teeth. Understanding the rate of reliability decline is crucial for optimizing operational efficiency and minimizing downtime. Following the evolution of reliability, it is observed that the probability that the sorting station trough will not fail after 182 days of operation is approximately 40% (Figure 13e), and to obtain an acceptable reliability of 80% (Figure 13f), the operating time decreases to 105 days of operation. There is a substantial drop in reliability (from 80% to 40%) in a relatively short period (182 \(-\) 105 \(-\) 77 days). This indicates a rapid rate of degradation or failure for the sorting station trough. Figure 13e highlights the need for reliability monitoring and preventive maintenance planning for the sorting station chute to ensure efficient and uninterrupted operations in the Patars quarry. A reliability of 40% after 182 operating days shows that there is only a 40% probability of the sorting station trough functioning without defects. Therefore, there is a 60% probability of the trough failing within this time period. This reliability value indicates significant wear or a predisposition to failures of the trough under the operating conditions of the Patars quarry. This suggests that frequent maintenance interventions or replacements are necessary to prevent unplanned production interruptions. The provided data points highlight a concerning trend of rapid reliability decline for the sorting station trough.