Learn what boundary value analysis tests should be performed when changing commission bandings in a sales system. Discover the key boundary values to test.
Table of Contents
Question
Sell-It-Cheap salesrooms organises general and specialist sales where items are sold to the highest bidder. There is a sliding scale of commission charges, based on the price of items sold, with lower-priced items attracting a higher percentage. All items sold have a price in multiples of £1.
Items sold for £150 or less attract a flat-rate fee of £7.00, items otherwise sold for less than £500 have a fee of 6% of the price realised. Items otherwise sold for less than £1000 have a 4.5% fee, with items otherwise sold for less than £5000 having a 3.5% fee. Any items sold for £5000 or more have a 3% fee.
Following customer feedback, Sell-It-Cheap have decided to change one of the existing commission bandings, with items sold between £500 and £749 having a 5.5% fee, and items otherwise less than £1,000 having a 4.5% fee.
What tests would be appropriate to test this change in commission bandings, using the 2-point boundary value analysis technique?
A. £748, £749, £750, £751.
B. No additional tests required; existing BVA tests can be used.
C. £499, £500, £749, £750, £999, £1000.
D. £500, £749, £999, £1000.
Answer
To properly test the change in commission bandings using 2-point boundary value analysis (BVA), the following tests would be most appropriate:
C. £499, £500, £749, £750, £999, £1000.
Explanation
Boundary value analysis is a black-box testing technique that focuses on testing at the boundaries of input and output equivalence classes. The 2-point BVA variant tests both on and just off the boundary values.
In this case, the change introduces a new banding for items sold between £500 and £749 with a 5.5% fee. Items sold for £750 to £999 now have a 4.5% fee.
The key boundary values to test are:
- £499 and £500 (boundary between the <£500 and £500-749 bandings)
- £749 and £750 (boundary between the £500-749 and £750-999 bandings)
- £999 and £1000 (boundary between the £750-999 and ≥£1000 bandings)
Testing both on (£500, £749, £1000) and just off (£499, £750, £999) these boundaries verifies that items are classified into the correct fee bandings right at and around the banding thresholds.
The other options are incomplete or incorrect:
A. £748, £749, £750, £751 only tests around the £749/750 boundary but neglects the other boundaries.
B. Additional tests beyond the existing BVA tests are required, as the banding boundaries have changed.
D. £500, £749, £999, £1000 tests on the boundaries but neglects to test just off the boundaries.
Therefore, option C represents the most thorough set of 2-point BVA tests to verify the new commission banding logic.
ISTQB CTAL-TA certification exam assessment practice question and answer (Q&A) dump including multiple choice questions (MCQ) and objective type questions, with detail explanation and reference available free, helpful to pass the ISTQB CTAL-TA exam and earn ISTQB CTAL-TA certification.