Good Test Case

A good test case is effective. That is, it will find a fault. This does not mean that a test case that does not find a fault is not a good one, since this implies that the fault that the test case could have found is not present (i.e. it gives us some confidence in the software, and this in itself has value). Perhaps we should say that a good test case has the potential to find a fault.

A good test case is exemplary; meaning that it does more than one thing for us (is capable of finding more than one fault).

A good test case is revolvable. As the software changes so too will some of the tests need changing to reflect different functionality, new features, etc. The effort to update test cases is usually very significant. However, much can be done when designing test cases to reduce or minimize the amount of maintenance effort needed to update test cases to make them compatible with later versions of the software.

A good test case is economic. A test case that requires 50 people to come into the office on a Saturday morning and all be poised at their keyboards at 9am is expensive to perform and it can only be run once a week. A test case that can be run at the touch of a button and only lasts two seconds is much more economic