What is Pairwise testing and does it require special software?

Question

What is pairwise testing? Is this method preferred over equivalence classes and boundary value testing? Does pairwise testing require the use of automated test case generation software?

Answer 1

All pairs or pairwise testing is simpler then you think. If you have 10 inputs and each input has 5 equivalence classes. You calculate the number of pair inputs which is the inputs - 1 summed. so 9+8+7+6+5+4+3+2+1 = 45. Then you take the equivalence classes^2 so 5^2 and you get 25. Then you multiply 25*45 = 1125 test cases.

I hope this helps.

Answer 2

Pairwise testing is the method to test the application for all possible inputs combination.

In market lot of Pairwise Testing Tools are available use below link as -

EX >> system has ten configuration parameters, and every configuration parameter has ten different values. To test that system behaves correctly with all the different configurations(around 10 billion combination) is not possible.

with the help of tool like (Allpairs, PICT etc) find a small set of test cases to satisfy that coverage standard.

The proposal of pairwise testing for above example is that it is enough to test for all the possible value combinations for any two of the ten variables.

Answer 3

pairwise testing is a combinatorial method of software testing that, for each pair of input parameters to a system (typically, a software algorithm), tests all possible discrete combinations of those parameters.

Here is a more detailed example: http://www.tutorialspoint.com/software_testing_dictionary/pairwise_testing.htm

The rest of your question is similar to this Equivalence Class Testing vs. Boundary Value Testing

Equivalence Class Testing EC Testing is when you have a number of test items (e.g. values) that you want to test but because of cost (time/money) you do not have time to test them all. Therefore you group the test item into class where all items in each class are suppose to behave exactly the same. The theory is that you only need to test one of each item to make sure the system works. Example 1 Children under 2 ride the buss for free. Young people pay $10, Adults $15 and Senior Citizen pay $5.

Classes:
Price:0 -> Age:0-1
Price:10 -> Age:2-14 
Price:15 -> Age:15-64
Price:5 -> Age:65-infinity 

Example 2 (more than one parameter) Cellphones K80, J64 and J54 run Java 5. K90 and J99 run Java 6. But there are two possible browsers FireFox and Opera, J models run FF and K models run O.

Classes:
Browser:FF, Java:5 -> Phones:J64,J54
Browser:FF, Java:6 -> Phones:J99
Browser:O, Java:5 -> Phones:K80
Browser:O, Java:6 -> Phones:K90

Dangers Of Equivalence Class Testing There is a danger of using EC Testing that is rarely mentioned in the testing books but is very important to remember. Just because two items/values are suppose to be in the same class and behave the same, does not mean they DO behave the same. That means that just because you test one value in the class that ALL values in the class behave the same. Real world example of mine is with cell phones that all had a certain Java Platform. They were suppose to all work the same but they didn't in reality. So testing just one value in a class is good, but not good enough. EC Testing is a good tool, but it's not fool proof and be careful with it. If test cases are cheap and fast (like automation), test more, or why not test them all!

Boundary Value Testing BV Testing is when you decide to test the values on the edge of each Class you have identified. The theory is that most defects is around the edges of a class. Example

Classes:
Price:0 -> Age:0-1 ( Boundary values 0, 1)
Price:10 -> Age:2-14 ( Boundary values 2, 14)
Price:15 -> Age:15-64 ( Boundary values 15, 64)
Price:5 -> Age:65-infinity ( Boundary values 65)