## 3 Results
For the month of proposal for change requests (Figure 3a) and the planned month for implementation (Figure 3b), there are no differences between the companies for the process types, i.e., engineering change or correction. Regarding the month of effective implementation of change requests, there are visible differences between the companies with respect to both types of processes. Regarding the year of proposal/initiation, the planned year for implementation, and the year of effective implementation of change requests, the data are presented in Figure 4, comparatively for the two companies. It can be seen that:  
* For company A, in 2018 from a total of 51 proposals, 45% of the change requests were planned and 14% of the change requests were implemented; the situation is much better in 2019 and in 2020, by increasing the number of effectively implemented change requests and including the previous change requests from 2018. * For company B, the situation is more equilibrated, although the number of change requests is superior compared with Company A.  
Figure 3: Boxplots for the month of proposal/initiation, the planned month for implementation, and the effective implementation month of change requests. (**(a)**—for month of proposal/initiation of the request change, **(b)**—for planned month of implementation of request change and (c)—for effective month of implementation of request change). \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multirow{3}{*}{**Month**} & \multicolumn{3}{c}{**The Month of Proposal/Initiation of**} & \multicolumn{3}{c}{**Planned Month for Implementing**} & \multicolumn{3}{c}{**The Month for Effective**} \\  & \multicolumn{3}{c}{**Change Request**} & \multicolumn{3}{c}{**Change Request**} & \multicolumn{3}{c}{**Implementation Month of Change**} \\ \cline{2-13}  & \multicolumn{2}{c}{**Company A**} & \multicolumn{2}{c}{**Company B**} & \multicolumn{2}{c}{**Company A**} & \multicolumn{2}{c}{**Company B**} & \multicolumn{2}{c}{**Company A**} & \multicolumn{2}{c}{**Company B**} \\ \cline{2-13}  & & **\%** & & **\%** & & **\%** & & **\%** & & **\%** & **\%** \\ \hline April & 19 & 8.8 & 40 & 5.4 & 16 & 7.4 & 46 & 6.3 & 8 & 3.7 & 37 & 5.0 \\ May & 15 & 7.0 & 53 & 7.2 & 26 & 12.1 & 55 & 7.5 & 12 & 5.6 & 62 & 8.4 \\ June & 20 & 9.3 & 63 & 8.6 & 14 & 6.5 & 57 & 7.8 & 15 & 7.0 & 52 & 7.1 \\ July & 28 & 13.0 & 75 & 10.2 & 27 & 12.6 & 76 & 10.4 & 26 & 12.1 & 72 & 9.8 \\ August & 16 & 7.4 & 44 & 6.0 & 24 & 11.2 & 50 & 6.8 & 16 & 7.4 & 54 & 7.4 \\ September & 16 & 7.4 & 53 & 7.2 & 9 & 4.2 & 54 & 7.4 & 27 & 12.6 & 50 & 6.8 \\ October & 19 & 8.8 & 68 & 9.3 & 14 & 6.5 & 65 & 8.9 & 24 & 11.2 & 64 & 8.7 \\ November & 12 & 5.6 & 54 & 7.4 & 11 & 5.1 & 55 & 7.5 & 36 & 16.7 & 58 & 7.9 \\ December & 15 & 7.0 & 67 & 9.1 & 23 & 10.7 & 66 & 9.0 & 25 & 11.6 & 71 & 9.7 \\ Total & 215 & 100.0 & 734 & 100.0 & 215 & 100.0 & 734 & 100.0 & 215 & 100.0 & 734 & 100.0 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: _Cont._In Figure 5 for Company A and in Figure 6 for Company B, we present the structures of the change requests' statuses. Figure 4: The distribution and structure of the year of proposal/initiation, the planned year for implementation, and the year of effective implementation of change requests. Figure 5: The structure of the change requests’ statuses for Company A. The situations are quite different: For Company A, most of the change requests are closed (75%) followed by local confirmation for implementation (8%) and canceled (8%); for company B, only 10% of the change requests are closed but 86% of the change requests receive local confirmation for implementation and 2% of the change requests already have manager approval. The structures of the types of processes proposed for change are presented in Figure 7. For Company A, the number of engineering changes is relatively equal with the corrections, but the structure is different for Company B with 66.3% correction and 33.7% engineering changes.