# Graph-Driven Exploration of Issue Handling Schemes in Software Projects
## 5 Experimental Results and Analysis
### Profiles of Issue Handling Paths
#### 5.2.1 Structural Features
The path state (PSp) profile for the 10 most populated paths of the MongoDB project is given in Table 6. The used state acronyms are defined in Table 3. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**N** & **AVE** & **Max** & **Q2** & **Q3** \\ \hline
2730 & NV,NS,OP,IPR,ICR,CLO & 19.4 & 511.0 & 5.8 & 19.0 \\
649 & NV,NS,OP,IPR,ICR,NM,CLO & 19.0 & 348.0 & 5.9 & 18.7 \\
513 & NV,NS,OP,ICR,CL & 10.7 & 372.8 & 3.3 & 8.4 \\
370 & NV,NS,OP,CLO & 47.0 & 693.6 & 11.1 & 39.9 \\
316 & NV,NS,CLO & 8.7 & 168.0 & 2.0 & 6.8 \\
236 & NS,OP,NS,IPR,ICR,CLO & 11.9 & 172.9 & 4.1 & 11.3 \\
229 & NV,CLO & 3.0 & 56.9 & 0.8 & 3.4 \\
209 & NV,NS,OP,IPR,CLO & 27.7 & 229.9 & 9.8 & 31.2 \\
174 & NV,NS,INV,IPR,ICR,CLO & 12.6 & 224.7 & 4.0 & 10.2 \\
124 & NV,NS,OP,BAC & 375.8 & 825.9 & 366.2 & 584.2 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Sample of bug issue handling paths for the MongoDB project. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**N** & **Path** & **AVG** & **MAX** & **Q2** & **Q3** \\ \hline
576 & N,IN,REV,TbT,V/C & 25.2 & 340.2 & 6.9 & 21.2 \\
106 & N,TbT,V/C & 29.8 & 332.3 & 3.8 & 17.3 \\
100 & N,V/C & 26.4 & 218.2 & 5 & 17 \\
48 & N,IN,REV,TbT,Ree,IN,REV,TbT,V/C & 60.3 & 283.7 & 30.3 & 65.4 \\
45 & N,NI,IN,REV,TbT,V/C & 46.1 & 212.9 & 15 & 49.9 \\
23 & N,IN,REV,TbT,Ree,TbT,V/C & 30.6 & 112.1 & 22.1 & 36.2 \\
22 & N,IN,N,NI,REV,TbT,V/C & 45.5 & 294.2 & 25.6 & 74.7 \\
21 & N,IN,V/C & 30.3 & 131.3 & 10.2 & 41.3 \\
19 & N,NI,FIPrS,V/C & 58.4 & 235.4 & 28.3 & 80.0 \\
18 & N,IN,NI,FIPrS,REV,TbT,V/C & 48.2 & 248.7 & 27.4 & 49.3 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Sample of bug issue handling paths for the project P1. A quite different PL\({}_{\text{P}}\) profile relates to the Log4J2 project (1423 bug issues):  
\(PL_{\text{P}}\) (Log4J2) = 9 (2, 2)--0.14%; 8 (5, 5)--0.35%; 7 (6, 6)--0.42%; 7 (9, 22)--6.3%; 5 (14, 42)--2.9%;  
4 (22, 111)--7.8%; 3 (44, 463)--32.5%; 2 (37, 771)--54.2%  
As compared with the presented profiles, PL\({}_{\text{P}}\) (P1) and PL\({}_{\text{P}}\) (MongoDB), PL\({}_{\text{P}}\) (Log4J2) comprises a lower number of paths (99) with a lower number of states (2-9). Two- and three-state paths are dominant (54.2% and 32.5% issue coverage). The 10 most populated paths are presented in Table 7 (PS\({}_{\text{P}}\) profile), covering 82.6% of bug issues. It is worth noting that most paths were terminated with a closed state (C). On the other hand, the structure of two-state paths was O, C (2.9%) and O, R_x (51.3%), where x corresponds to diverse issue resolution types, e.g., fixed (F), not a problem (NP), invalid (I), cannot reproduce (CnR), rejected (R), duplicated (D), etc. Handling times for the O,CnR path (14 issues) was very high (AVG, MAX, Q2, and Q3: 610.7, 2598.7, 206, and 619.8 days, respectively) due to the high effort required in reproducing the bug, probably resulting from inaccurate issue specification. The duplicate issues (path O, R_D) were detected quite fast (Q2, Q3: 1.5, 14.1 days); however, in case of one issue, over 2000 days was required. The presented path profiles provide some perspectives on the path diversity, the impact of restriction (R) on the considered issues, etc. Having analyzed the path profiles for other open source projects, we also found projects with paths involving a lower number of states, e.g., 2-10. In two other commercial projects (A and B), the path structures involved 2-15 states. However, in a complex long-term commercial project, C [13], path lengths resulted in 4-44 states with a total number of paths of over 1500, covering issues at rate ranging from a fraction of a percent up to 10%. So, the dominating paths were not uniquely obvious. This was a long-term project with high fluctuation of actors. Moreover, the large number of used states created possible high path diversity. Higher path diversity is typical in projects involving many states. Issue flow coverage for longer paths is usually lower than for typical ones.