Case1:
while testing is inprogress finding the design level
(coding) issue:
stop the testing and arranging design review.
case 2:if the test case design is wrong, while progessing 
testing.then stop the testing and change the test case 
design hwich should match desgin and then testing from the 
top to bottom.Specially need to test the scenarion which 
was tested using old (wrong) design.

Case3:
Before testing starts if the design(code or test case0 is 
wrong,:
then until getting the authorization of design docs testing 
should not start.