This post will see more details added to the defect report that provides a lot of useful information to the team. The last post talked about the flow of incoming defects that move to the ToFix state. However, there is another type of information that is relevant. Defects that are present in the system are not only owned by the development team. In addition to the defects in core code, there may be defects that are present in the components used in the application. These are defects that are not attributable to the development team, but to the vendors or other groups that provide the components. A number of teams that I know typically track these defects in the defect database, but distinct from the defects with the core team.
The nature of defects that are against external components is different from those in the core code. Even though to the customer it does not matter whether the defect is within the core code or in an external component, the amount of effort required in terms of coordination and communication is entirely different from the other defects that are with the core developmental team. If a defect is with a component that is not owned by the team, the timeline for fixing of the defect may take longer and need persuasion; or there may be a lot of back and forth between the tester and the external component team to study the situation in which the defect occurs (which also includes sending the environment in which the defect occurred to the external vendor - and this has its own cost and restrictions, since if the team is working on a new version of the software, there would NDA issues and IP issues related to sending details of the environment to the external component team), and so on. Another concern could be that that even if such a defect is resolved, it might need a new version of the component, which has its own extra cost about testing the component on its own to check whether it is fine or there are other issues with the same.
As a result, it needs to separate out the incoming defects about whether they belong to the core team or whether they are attributable to people outside the team; and if the proportion of such defects that are outside the core team is increasing, it is a matter of concern to the team, since resolving such defects typically takes much more effort and time.