Disable the New Defect button
In order to make sure that the test case are linked to the defects and the defects to the test cases, it is recommended to disable the New Defect button from the Defect Module. That way tester will be force to create the defects from the failed test cases and the links of those test cases to the defects will be added automatically.
Re: Disable the New Defect button
While this may sound like a good idea on the surface, doesn't it discourage the testers from putting defects into QC/ALM in a timely fashion.
This is particular troublesome for one offs such as deployment defects created by a mis-configuration at deployment.
I just think an organization need to carefully think about their situation, before making such a broad change in their organization.