You could expand the tag cloud concept by creating a new graph which would show defect trends. So, perhaps there are 10 items in the tag cloud which correspond to my defect taxonomy. I want to be able to show that we are decreasing the amount of failure demand in our system. A histogram or line graph showing how the say ten items in my defect taxonomy are trending over time would help give visibility. It would be helpful to be able to select the items in the defect taxonomy I am interested in.