When being used the QA team will schedule package testing sprints to happen during the cycle between milestone testing to ensure applications that are included in Xubuntu have sufficient amount of testing conducted.
Regardless of whether package testing is taking place during a development cycle, additional testing should be conducted for a new default application is to be included in the next Xubuntu release, when an existing application has a substantially large update in the middle of the cycle or when developers request specific testing for a specific update to an application.
Calls for package testing sprints will be sent out as required.