Istqb Certified Tester Foundation Level CTFL · Free Practice Question Medium
Question 79
Which of the following is true regarding the following state transition diagram:
-
A
The MINIMAL number of test cases required to cover all valid transitions is 2 starting form S2.
-
B
The MINIMAL number of test cases required to cover all valid transitions is 1 starting form S1.
-
C
The MINIMAL number of test cases required to cover all valid transitions is 2 starting form S1.
-
D
The MINIMAL number of test cases required to cover all valid states is 2 starting from S2.
Reveal correct answer
Correct answer: C
Explanation
If we start from S1:
In the first test case, we will go in the following order:
S1->S5->S1->S2->S4
In the second test case we will go in the following order:
S1->S2->S3
This provides 100% valid transition coverage with only two test cases.
=============
If we start from S2, it is impossible to achieve 100% valid transitions coverage because you can't move from S2 to S1 and this makes all transitions that are related to S1 & S5 not covered.
Discussion
Think the marked answer is wrong, or have a better explanation? Share it below — comments appear after review.
