###Discover the actual/prospect usage matrix to drive testing based on risk:(Sample Matrix)
Discover the actual/prospect usage matrix to drive testing based on risk:(Sample Matrix)
Testing is purely risk driven activity. I would suggest to find out the production usage base matrix (OS/Browser/devices wise) to find out the actual risk to drive the test efforts accordingly.
It only makes sense to test on wider combinations of configurations if the actual/future prospective usage is expected to be on that scale otherwise it should be tested functionally only on major OS/Browser/Device combinations.