Decision tables as test design process

The International Software Testing Qualifications Board (ISTQB®) is a non-profit certification body made up of expert committees acting on a voluntary basis. It has developed a global training with ISTQB Certified Tester.

In the ISTQB® Certified Tester Foundation Level Syllabus decision tables are presented as a good opportunity to create system requirements containing logical conditions.

Complex rules are described in a complete and unobjectionable fashion with an aid of decision table technology.

Test analysts use decision tables to provide a good sample of the necessary test cases. If the requirements are not specified yet as a decision table, the transformation of text in a decision table is a strong method of detecting omissions and conflicts in requirements.

If requirements are formulated directly as a decision table, the decision table can be used to estimate the expenditure for test case creation and test execution.

Each rule contains conditions that can be understood as preconditions or entries. The actions of a rule can be used to determine the system’s output and therefore the necessary checks. Each rule thus corresponds to one test case.

In a good test execution at least one test case is created for each rule and the provided test cases are e­xe­cu­ted. This corresponds to 100% rule coverage and thus a simple metric is specified in order to safeguard the quality of test execution.