You can work on existing issues in a number of ways. You can be assigned an issue as follows:
Responsible for an entire issue If you have been assigned responsibility for an entire issue, you are responsible for resolving the issue on time. You can, for example, change the priority and status of an issue, assign action items, calculate the effort required, describe steps to be taken to deal with an issue, and decide when an issue is closed.
Responsible for a specific action item If you are assigned a specific action item, you help resolve the issue, but do not have overall responsibility for it.
Any corrections you make on the Effort tab are recorded and included in reports.
Working on and Closing Issues 
