![[Level:12]](http://www.vietnamesetestingboard.org/zbxe/modules/point/icons/default/12.gif "Point:4380point (8%), Level:12/30"){kind=icon}
nhlamAchieving a 100% tested product is realistically impossible. Testing is expensive. However, defects discovered after deployment are far more costly than those found prior to deployment. The objective is to do enough testing that the risk of finding a post-deployment defect becomes acceptable. Put another way, test until the cost of repairing the defect is less than finding it via testing.
The art of testing is to find that optimum point, based on the number of suspected defects remaining. It is always better to err on the side of more testing when that point appears as a grey-area.
Testing organizations have two ways to move that point further to the right without incurring hits
against cost or resources: look for ways to test faster and look for ways to avoid extensive testing
where defects are not suspected (allowing the remaining time for other important tests).
![[Level:5]](http://www.vietnamesetestingboard.org/zbxe/modules/point/icons/default/5.gif "Point:900point (45%), Level:5/30"){kind=icon}
![[Level:23]](http://www.vietnamesetestingboard.org/zbxe/modules/point/icons/default/23.gif "Point:16380point (36%), Level:23/30"){kind=icon}
thanks