# Survivability Prediction of Open Source Software with Polynomial Regression
## 4 Results and Analysis
### RQ1: Experiment Results  
To address RQ1, we analyzed the condition of OSS predicted to deteriorate based on survivability forecasts. Furthermore, we compared the survivability and condition of each OSS to identify the factors influencing the outcomes. The analysis of five OSS projects is depicted in Figure 9, which illustrates the changes in the number of remaining bugs over time for each OSS. Additionally, information regarding these OSS projects is presented in Table 5.  
Among the five OSS projects, CodableCSV exhibited the highest \(\mathit{Trend}_{\mathit{bug}}\) value, indicating a significant decrease in bug-fixing activities or an increase in bug issues compared to other OSS, leading to the lowest survivability among the five. Table 5 shows that CodableCSV had the lowest number of contributors among the five OSS projects. Despite being one of the oldest OSS in the group, normalize.css recorded the lowest metrics. However, \begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Metric** & **Degree 2** & **Degree 3** & **Degree 4** & **Degree 5** \\ \hline Mean of RMSE & 1.3100 & 99.6080 & 83,642.7561 & 33,254,864.4670 \\ Mean of RSE & 0.0101 & 0.0056 & 5.4098 & 2.5035 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Model evaluation results by degree 2–5. Figure 9: Change in bug-fixing activities of OSS. like CodableCSV, it has no currently active contributors, yet the two exhibited significant differences. The reasons for these differences, as identified through our analysis, are as follows:  
1. normalize.css is over twice as old as CodableCSV, which may have led to a slower decline in community and development activities, resulting in less fluctuation in activities and a lower trend. 2. Compared to CodableCSV, normalize.css has approximately 150 times more forks and 10 times more stars. These characteristics contribute to the differences in GitHub issue activities between the OSS projects. CodableCSV has fewer new issues and a similarly low pull request activity. In contrast, normalize.css continues to generate a significant number of issues and, accordingly, more pull requests. Therefore, while CodableCSV might not be maintained further due to a lack of users and contributors, normalize.css seems more likely to find individuals to continue its legacy due to sustained interest. Realm SwiftLint has been around for 8 years, CocoaPods for 12 years, and Sentry Cocoa SDK for 7 years, all considered to be relatively old but predicted similar metrics. The presence of currently active contributors in these three projects seems to prevent their \(\mathit{Trend}_{bug}\) from appearing high. However, despite being as old as normalize and having active contributors, CocoaPods showed a higher \(\mathit{Trend}_{bug}\) value, likely due to generating bug issues more frequently and quickly than normalize.css. Based on these metrics, if one were to choose an OSS for replacement, CodableCSV, which displayed the highest \(\mathit{Trend}_{bug}\), should be selected. The current status of each OSS is as follows:  
CocoaPods is a library for managing dependencies in Xcode projects, developed over 12 years. It currently has three active developers, with 13 commits made last month. However, there are about 53 unresolved bug issues, and numerous issues continue to be reported. The high number of unaddressed issues suggests a lack of sufficient contributors to manage the workload. CodableCSV is a library offering comprehensive functionality for reading/writing CSV files, developed over 5 years. However, it currently has no active contributors, leading to a complete halt in commit activities. As the system's versions continue to increase, the likelihood of it failing to keep up with these versions also increases. normalize.css is a library created 12 years ago to enable browsers to render all elements more consistently. As indicated in Table 5, it currently has no commit activity and lacks contributors, presenting a risk similar to CodableCSV of failing to adapt to later upgraded versions.