# A Rule-Based System for Human Performance Evaluation: A Case Study
## 5 Discussion  
One of the key phases when designing an ES is to conduct adequate data analysis. That is the main difference compared to preliminary research conducted in [8], which has proved ES as a successful tool for waste elimination within processes. In this paper, the focus is on the parameter definition. The data analysis is performed in two senses in order to determine the relationship between observed parameters and to determine associations within a certain parameter for 11 PTI inspectors before and after the PTII WQA ES application. The purpose of the data analysis was to determine which parameters are indeed crucial for designing rules within ES and for their future monitoring. Therefore, the question was posed whether the observed parameters affect the PTI result. A binary logistic regression has shown that PTI result can be predicted based on the vehicle age with a \(p\)-value of 0.000000 and duration of the PTI with a \(p\)-value of 0.000080 at the significant level of 0.05, indicating the fact that both variables are significant and relevant for designing rule-based PTII WQA ES. An ANOVA analysis pointed to the fact that PTI inspectors significantly differ in regard to the duration of the PTI. In this case, the binary logistic regression and an ANOVA test have confirmed the significance of experiential parameters that were assessed in the standard evaluation system. In the ES design process, the rules were generated not only considering the experience of the expert but focusing on standards prescribed by legal regulations, professional instructions, and average values of the observed sample. A similar method for designing rules is shown in [23], where authors used technical reports. Thus, the subjectivity of the ES and proposed decisions is reduced. In order to demonstrate the positive impact of PTII WQA ES application within the process, the hypothesis was proposed. The application of the PTII WQA ES has resulted in the improvement of the work results as soon as in the first year of application. The PTII WQA ES has resulted in reducing the difference in the average PTI duration of 11 PTI inspectors. An ANOVA test has established that the number of homogeneous groups increased from five (before application) to seven after the PTII WQA system application. In addition, more uniform performance of PTI inspectors has been achieved, which confirmed the hypothesis. The goal of the ES implementation in this area is not to replace an expert in making decisions regarding employee performance but to help him to make efficient decisions in real-time and to help other non-experts to understand them. Furthermore, the purpose of \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Count** & **Mean** & **Homogeneous Groups** \\ \hline Duration\_PTII7 & 2293 & 26.7457 & X1  \\ Duration\_PTII10 & 2219 & 28.014 & X \\ Duration\_PTII3 & 2281 & 28.7979 & X \\ Duration\_PTII8 & 2193 & 29.3092 & XX \\ Duration\_PTII4 & 2222 & 29.3267 & XX \\ Duration\_PTII6 & 1914 & 29.7576 & X \\ Duration\_PTII11 & 1961 & 30.4345 & X \\ Duration\_PTIII & 2158 & 30.6803 & XX \\ Duration\_PTII2 & 1123 & 31.3785 & XX \\ Duration\_PTII9 & 1362 & 31.6593 & X \\ Duration\_PTII5 & 2208 & 31.8886 & X \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Multiple range test after the application of the PTII WQA. the PTII WQA ES was not to sanction the inspectors who deviate from reference values but to educate and train them, all in order to establish a more objective and efficient PTI system. Research conducted in [26] yielded similar findings. The authors as well emphasized that the proposed ES provides a foundation for performance evaluation and great support to managers regarding decision-making. The limitation of the conducted research primarily relates to the lack of benchmarking in the research area regarding ES implementation within the process of human performance evaluation, as indicated in [25].