## 3 Results
Table 8 also presents the results of the Mann--Whitney test for independent samples for a comparison of the status of change requests between the two companies; the results indicate that there are statistically significant differences between the researched companies, and they practically confirm the visible differences shown in Figures 5 and 6. Regarding customer involvement in change requests, for company A, there is clients involvement in only 25% of the change requests, and the results of a chi-square test indicate that there are no differences according to customer involvement in change requests with respect to the status of change requests (\(p\)-value = 0.213). However, the ANOVA test results indicate that, according to customer involvement in change requests, there are statistically significant differences with respect to the number of days from creation to planning of change requests (Table 9). \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline  & \multicolumn{3}{c}{**Leverner’s Test for**} & \multicolumn{3}{c}{**\(t\)-Test for Equality of Means**} & \multicolumn{3}{c}{**\#S. Confidence**} \\  & \multicolumn{1}{c}{**F**} & **Sig** & **t** & **df** & **Sig** (\(\frac{\text{Q-width}}{\text{Q-width}}\))** & **Mean** & **Sid. Error** & **Impact of the Difference** & **Difference** \\ \hline  & & & & & & & & **Lower** & **Upper** \\ \hline The number of days from motion to & Equal variations assumed & 241.384 & 0.000 & 35.873 & 360 & 0.000 & 3.644 & 0.101 & 3.446 & 3.812 \\ planning of change requests & Equal variations not assumed & & 25.367 & 245.209 & 0.000 & 3.614 & 0.142 & 3.333 & 3.894 \\ \hline The number of days from planning to & Equal variations assumed & 1099.307 & 0.000 & 10.008 & 397 & 0.000 & 1.075 & 0.106 & 0.866 & 1.284 \\ effective implementation of change requests & Equal variations not assumed & & 6.627 & 230.443 & 0.000 & 1.075 & 0.107 & 0.546 & 1.404 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Results of the Student’s \(t\)-test for independent samples. \begin{table}
\begin{tabular}{c c c c} \hline \hline  & **Null Hypothesis** & **Test** & **Sig.** & **Decision** \\ \hline  & The distribution of the month of & Independent Samples & \\  1 & proposal/initiation of request for change is the & Mann–Whitney U Test & 0.873 & Retain the null \\  & same across categories Company A/Company B & & \\ \hline  & The distribution of planned month for & Independent Samples & \\
2 & implementing of request for change is the same & Mann–Whitney U Test & 0.975 & Retain the null \\  & across categories Company A/Company B & & \\ \hline  & The distribution of effective implementation & \\
3 & month of proposal/initiation of request for & Independent Samples & \\  & change is the same across categories Company & Mann–Whitney U Test & 0.000 & Reject the null \\  & A/Company B & & \\ \hline  & The distribution of status of change request is the & Independent Samples & 0.000 & Reject the null \\  & same across categories Company A/Company B & Mann–Whitney U Test & 0.000 & Reject the null \\ \hline  & & & & & \\ \hline  & & & & & \\ \end{tabular}
\end{table} 
Table 8: Results of the Mann–Whitney test. Therefore, for Company A, customer involvement in change requests, even a small percentage, does not influence the change request status but it can influence the number of days between creation/proposal of change requests and planning of change requests for implementation. To determine the best predictors of change request status (as the dependent variable) for each company, we applied multilinear regression models with Enter method and the following independent variables: the number of days from planning to effective implementation of change requests, the number of days from creation to planning of change requests, the effective implementation month of change requests, the month of proposal/initiation of change requests, the planned month for implementing change requests, and the type of process proposed for change.