# 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
Independently of the assumed IHM restrictions (R), the highest issue coverage is assured by paths with five and six states. For bug issues covering the period of 2017-2021 (4545 issues, 1070 paths), we obtained paths covering 2-50 states: paths with over 13 states covered 0.02-1% (total 4.8%) of the issues, while 6 state paths (119) covered 40.42% of the issues. A higher number of long paths can be attributed to the higher fluctuation of staff and the lower experience as compared with period of 2022, where the number of states was reduced due to discussions after analyzing the statistical results. Another observation perspective is the path state (\(\mathrm{PS}_{\mathrm{P}}\)) profile. In Table 5, we present 10 paths with the highest coverage (N) for project P1, extended by the timing features (in days) discussed in Section 5.3. Specifying path states, we use the following state acronyms: _New_ (N), _In Progress_ (_IN_), _To be Tested_ (_TbT_), _Verified_/_Closed_ (_V/C_), _Reopened_ (_REO_), _Need Info_ (_NIF_), _Review_ (_REV_), _Backlog-not ready_ (_BN_), _backlog-Ready_ (_BR_), and _Done_ (_D_). It is worth noting that 68% of the paths cover single issues, resulting in 15% of all handled issues overall. Due to the high diversity of paths, we recommend using some aggregation in the analysis (Section 5.3). For the open source project MongoDB, the ITS repository (covering 2 years) comprised 13,435 issues (8405 bug issues--7385 closed; 4257 improvement--3155 closed; 773 new feature--625 closed). The derived \(\mathrm{PL}_{\mathrm{P}}\) profile for the 832 unique paths was as follows:  
\(\mathrm{PL}_{\mathrm{P}}\)_(MongoDB) = 28(1;1)--0.01%; 27(1;1)--0.01%; 23(1;1)--0.01%; 22(2;2)--0.01%; 21(8;8)--0.06%; 20(6;6)--0.04%; 19(7;7)--0.05%; 18(9;9)--0.07%; 17(12;12)--0.09%; 16(17;17)--0.13%; 15(26;24)--0.19%; 14(34;30)--0.25%; 13(43;39)--0.32%; 12(102;84)--0.76%; 11(121;91)--0.9%; 10(295;158)--2.2%; 9(400;172)--2.98%; 8(686;157)--5.11%; 7(1948;159)--14.5%; 6(5023;11)--37.39%; 5(1630;71)--12.13%; 4(161;74)--12.04%; 3(1161;22)--8.64%; 2(283;7)--2.11%; 1(2;2)--0.01%;Limiting IHM to bug issues (restriction R), we obtained 8405 issues (510 open) handled by 832 unique paths with the following distribution: (10-28)--2.45%; (7-9)--21.98%; (6)--41.22%; (2-5)--31.97%. For issues with the highest priority (54 blocker issues, 15 unique paths), the distribution was as follows: (8-10)--9.26%; (6-7)--72.2%; (2-5)--18.52%. For the lower-priority issues, the path length diversity was higher: _Critical_ (2-16)--123 issues; _Major_ (2-27)--7488 issues; _Minor_/_Trivial_ (2-14)--231 issues. We identified that 69.9% of paths (586) were related to single issues, and they covered only 7% of all issues. The length of most of these paths ranged from 10 to 27 states; however, some short paths (with strange state sequences) occurred also, e.g., 14 paths involving three states. On the other hand, the 10 most populated paths (with a length range of 1-6) covered 67.9% of all bug issues. The number of unique paths (length 1-9) covering 10 or more issues was 56, covering 85% of issues overall. Paths covering more than 10 issues contributed 69.9% of the paths. The dominant path length was 6, relating to 95 paths which covered 40.42% of issues. We can also derive path profiles for issues of specified priorities. Issues with the priorities _blocker_ (54), _critical_ (121), _major_ (7481), and _trivial_/_minor_ (231) were handled by paths with length ranges of 2-10, 2-16, 2-28 and 2-14, respectively. It is worth noting that there are many long paths (high diversity). However, they are linked to a small number of issues; nevertheless, in total, they can cover a significant percentage of issues. The ratio of paths covering only a single issue related to all issues for the considered priorities in the considered project was 0.67, 0.82, 0.68, and 0.66, respectively. For _Improvement/new features_ issues (5030 issues including 3780 closed issues and 760 paths), the path lengths ranged from 1 to 27, with dominant coverage for 3-7-state paths, covering 85% of issues.