CTAL-TTA Exam Dumps : Certified Tester Advanced Level Technical Test Analyst

The control flow graph provided illustrates the decision points for an airline's upgrade and boarding process. Decision coverage is a measure of the percentage of decision points executed during testing:

Test 1 covers the decision points: Gold card? (Yes) and Business full? (No).

Test 2 covers: Gold card? (No) and Economy full? (No).

Test 3 covers the decision that leads to being bumped from the flight, which is Economy full? (Yes) and Business full? (Yes).

From the given tests, the decision points for Gold card? (No) and Business full? (No) are not tested, leaving us with 4 out of 6 decision points covered, which is approximately 67% decision coverage.

Installability testing is usually conducted during the System Testing stage of the SDLC. It typically includes testing the installation process of the software to verify that it installs correctly across various systems and configurations. This type of testing often overlaps with functionality testing to ensure all functions are available post-installation, and usability testing to ensure that the installation process is intuitive and user-friendly.

Explanation: System testing encompasses a broad spectrum of testing practices intended to validate the software in its entirety, ensuring it meets the specified requirements and is ready for operation.

To achieve 100% decision coverage, we need to ensure that every decision (if statement) in the code has been tested for both true and false outcomes. Let's analyze the code and count the decisions:

IF (Room_price > 200)

IF (Loyalty_level = Platinum) inside Room_price > 200

ELSE within the same decision above

IF (Loyalty_level = Gold) inside the ELSE of decision 2

IF (Room_price > 150)

IF (Loyalty_level = Platinum) inside Room_price > 150

ELSE within the same decision above

IF (Discount_factor < 100%)

To cover all these decisions, we need test cases for each possible combination:

Room_price > 200 and Loyalty_level = Platinum.

Room_price > 200 and Loyalty_level = Gold.

Room_price > 200 and Loyalty_level not Platinum or Gold.

Room_price <= 200 and Room_price > 150, and Loyalty_level = Platinum.

Room_price <= 200 and Room_price > 150, and Loyalty_level not Platinum.

Room_price <= 150.

From these scenarios, we can see that the minimum number of test cases required to achieve 100% decision coverage is four:

Test with Room_price > 200 and Loyalty_level = Platinum (tests decision 1 true, 2 true, and 8 true).

Test with Room_price > 200 and Loyalty_level = Gold (tests decision 1 true, 2 false, 4 true, and 8 true).

Test with Room_price > 200 and Loyalty_level not Platinum or Gold (tests decision 1 true, 2 false, 4 false, and 8 true).

Test with Room_price <= 200 and Room_price > 150, and Loyalty_level = Platinum (tests decision 1 false, 5 true, 6 true, and 8 true).

Test with Room_price <= 200 and Room_price > 150, and Loyalty_level not Platinum (tests decision 1 false, 5 true, 6 false, and 8 true).

Test with Room_price <= 150 (tests decision 1 false, 5 false, and 8 false).

Given that these six cases test all branches, four test cases are required to ensure that all decisions are covered at least once.

Therefore, the correct answer is A. 4.