# Management System According to ISO/IEC 17025: Method Validation
## 2 Materials and Methods
Similarly, the accuracy of a measurement system comprises components of variation associated with the measurement instrument, which can be minimized or reduced to an acceptable extent through proper calibration within required intervals. The accuracy of a measurement system consists of two main components:  
Repeatability: variation can be caused by the measurement device and is observed when the same operator measures the same item multiple times using the same measurement system under identical conditions. Reproducibility: variation can be caused by the measurement system and is observed when different operators measure the same item multiple times using the same measurement system under consistent conditions. Conducting a repeatability and reproducibility study helps assess the performance of the measurement system and ensures that it meets acceptance criteria through an analysis of performance data. Therefore, to evaluate the precision of a measurement system, it is recommended to utilize r&R (repeatability and reproducibility) studies. These studies measure the error generated by the two components mentioned earlier and also provide insight into the intrinsic variability within the measurement system, which can be challenging to control. In essence, r&R studies compare the variation in the measurement system components with their total variation and tolerance. The methods employed to conduct r&R studies include the following:  
Range method (also known as the short method);  
Average and range method (also known as the long method);  
Variance analysis method (also known as the Anova method). Indeed, the variance analysis method presents several advantages compared to the first two methods. Firstly, it offers a more accurate estimation of variances, providing a better understanding of the variability within the measurement system. Additionally, it yields valuable additional information, such as identifying operator interaction with the item being measured. Moreover, the variance analysis method considers a random effects model for all factors or components of the system's variation, including operators, items, interaction, and instrument. This comprehensive approach ensures a thorough assessment of the measurement system's performance and helps in identifying sources of variation that may affect the accuracy and reliability of the measurements. The standard ANOVA table, which includes the formulas for the sums and mean squares of each system variation component, is presented in Table 2[13]. Derived from the fact that the anchor test installed inside the mine is a destructive test, the same sample cannot be measured multiple times. Therefore, it was decided to perform tests at different points while maintaining consistency in the supplier of the anchor rods. This approach aims to reduce potential sources of variation in the measurement system. Additionally, it is important to note that ASTM (D4435) highlights the precision required for such tests. Given the nature of the rock materials involved, it is often impractical or prohibitively expensive to produce multiple samples with uniform physical properties. Consequently, the focus is on minimizing variation stemming from sample properties, operator technique, or laboratory conditions (ASTM). 4. The Evidence of an Inter-Laboratory Comparison:  
The final requirement mandated by the accrediting body is an inter-laboratory comparison, as stipulated in the standard ISO/IEC 17025:2017 for precision assessment. Inter-laboratory comparison involves the measurement of the laboratories' performance and the evaluation of test results of the same item or similar items by two or more laboratories under predefined conditions. To fulfill this requirement, the company \"Mining Industry X\" was invited to participate in conducting tests on 5/8 anchors. The results obtained from these tests are presented in Table 3. Subsequently, the repeatability and reproducibility calculations were performed, as shown in Table 3.