Domain Testing: Divide and Conquer - Testing Education

change has caused something that used to work to now be broken. ( pp. 40-
41)
2.03 Testing Multiple Variables in Combination
While testing multiple variables together, a test case represents a combination of
input values of these multiple variables. As noted in the introductory chapter, one
would ideally test for all possible combinations of inputs. But this is practically
impossible because even with a normal commercial program with few variables, all
possible combinations can lead to combinatorial explosion. The following are some
of the techniques described in the literature that involve combination testing of
multiple variables with a reduced test case set:
items.
• Cause-effect graphs
• Combinatorial testing using input-output analysis
• Pairwise or orthogonal arrays testing
• All pairs combination testing
• Weak robust equivalence class testing
The following sections include brief discussions of each of the above-listed
2.03.01 Cause-Effect Graphs
Bender (2001), Elmendorf (1973), Elmendorf (1974), Elmendorf (1975), Myers
(1979), and Nursimulu and Probert (1995) described cause-effect graphing as a
combination testing technique. To start with, using the specification of the program
under test, one identifies causes, effects and constraints due to the external
environment. Next, Boolean graphs are formed with causes and effects as the nodes
and the links joining causes and the respective effects that represent the relationship
between the causes and effects. The graph is then traced to build a decision table,
which is used to produce test cases.
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