Blocking Defects section of TCER
2 answers
The blocking defects are explicitly set by the users. It can be done from the "Manage Blocking Defects" action in the Test Case Execution Records list view to create new or add existing defects as blocking, or from the Defects section of an associated execution result to set/clear defects from the execution to be blocking.
Typically blocking defects are used when you have defects that prevent you from running the TCER. In that instance, there will be no Execution Results created. We use it for example when we already have run a TCER for another test case and know that others will fail because of the defect so there is no sense in attempting the follow on test cases.