Using the state transition test technique, how many 0-switch test cases are needed to achieve 100% 0-switch coverage?

A PIN entry component of an ATM system has been developed using the following state table:

Using the state transition test technique, how many 0-switch test cases are needed to achieve 100% 0-switch coverage?
A . 4
B . 7
C . 8
D . 28

View Answer

Answer: C

Explanation:

A 0-switch test case is a test case that covers one transition from one state to another. To achieve 100% 0-switch coverage, all the transitions in the state table must be tested. There are eight transitions in the state table, as shown by the arrows. Therefore, eight 0-switch test cases are needed.

Reference =

ISTQB Certified Tester Advanced Level Syllabus Technical Test Analyst1, page 2

How to Design Test Cases Using State Transition Testing Technique?2, section “0-switch coverage” 0 and 1 – Switch Coverage in State Transition Testing?3, answer by Marco Filippone