Domain Testing: Divide and Conquer - Testing Education

Appendix B: Guidelines for filling in “all-pairs combination”
table (continued)
in a circular list. For the first set you enumerated the values starting from first and
then second until finally you reach the first (which you just skip). Now, for the
next set start at the second value followed by the third value and so on and so
forth. By doing so, you will completely fill the column corresponding to the third
variable. The above described procedure for filling in columns corresponding to
first, second and third variable ensures that all-pairs has been achieved for the first
three variables.
12. For each variable after the third one, if there is any, for every set, you have to
order the test case values corresponding to the variable such that the final ordering
of all sets corresponding to the variable, results in each value of the variable being
paired with each value of every preceding variable. It might be required to
backtrack if the current ordering makes it impossible to achieve the above
mentioned end result. If, no matter what ordering you try and no matter how much
you try to backtrack and redo the things, the end result (all-pairs) in not achieved
then additional combinations might have to be added. Also note that it is possible
that there is multiple occurrence of a pair of values of two variables since all-pairs
technique only ensures that every value of a variable is combined with every
value of every other variable at least once not only once but the former is the
minimal requirement.
© Sowmya Padmanabhan, 2003
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