A small introduction to some techniques of BBT as Boundary Value, Equivalence Class, Decision Table. According to this presentation, you can know how to apply them in the real world.

1. Black Box Testing

2. What is Black Box Testing?
• BBT is a method for software testing.
• See the Black Box !
• Based on Requirements and Specifications of Software
• It’s know by name Behavior Testing

3. Advantages
• Test is executed from the user’s point of view or tester. So that, the
software is used from the objective perspective of end user.
• Avoidance of developer-bias
• Don’t need to know the programing language or how the software
implemented.
• Be able to write test case and execute test as soon as the
requirements are completed.

4. Disadvantages
• If requirements are not clearly, it might design test case wrong or it’s
hard to design test case.
• Just can test on the number of inputs so it will not cover all of the
cases.

5. Boundary Value Analysis (BVA)
• Faults tend to lurk near boundaries
• Good place to look for faults
• Test values on both sides of boundaries
1 100 1010
invalid invalidvalid

6. Equivalence Partitioning
• Divide (partition) the inputs, outputs, etc. into areas which are the same
(equivalent)
• Assumption: if one value works, all will work
• One from each partition better than all from one
invalid invalidvalid
1 100 1010

7. Example1: Enter description for case
• A test box allow input less than 400 characters

8. Description for case
Number of characters:
1invalid valid0
Conditions Valid Partition Invalid Partitions Valid Boundaries Invalid Boundaries
Description for
case
1 to 400
characters
< 1 character 1 character Empty
> 400 characters 400 characters 401 characters
400 401 invalid

9. Decision Table
• Determine the test scenarios for complex business logic.
• Identify a suitable function or system which reacts according to a
combination of inputs or events
• It is better to deal with large numbers of conditions by dividing them
into subsets and dealing with the subsets one at a time.
• Once you have identified the aspects that need to be combined, then
you put them into a table listing all the combinations of True and
False for each of the aspects

10. Example 2: Discount fee application
• A application for discounting the fee for the customer will follow by
the rules:
• If this is a new customer then she is discounted 15%
• If this is a loyalty customer then she is discounted 10%

11. Decision Table
Conditions Rule 1 Rule 2 Rule 3 Rule 4
New customer (15%) T T F F
Loyalty customer (10%) T F T F
Formula = 2n
N: The number of conditions

12. Decision Table
Conditions Rule 1 Rule 2 Rule 3 Rule 4
New customer (15%) T T F F
Loyalty customer (10%) T F T F
Actions/Outcomes
New customer (15%) Y Y
Loyalty customer (10%) Y Y

13. Decision Table
Conditions Rule 1 Rule 2 Rule 3 Rule 4
New customer (15%) T T F F
Loyalty customer (10%) T F T F
Actions/Outcomes
New customer (15%) Y Y
Loyalty customer (10%) Y Y
Error Message
Y

14. Decision Table
Conditions Rule 1 Rule 2 Rule 3 Rule 4
New customer (15%) T T F F
Loyalty customer (10%) T F T F
Actions/Outcomes
New customer (15%) Y Y
Loyalty customer (10%) Y Y
Error Message
Y Y

15. Output for each test case
Conditions Rule 1 Rule 2 Rule 3 Rule 4
New customer (15%) T T F F
Loyalty customer (10%) T F T F
Actions/Outcomes
Result Error Message Logic for New
customer
Logic for Loyalty
customer
Error Message

16. Advandtages vs Disadvantages
• Advandtages:
Test all cases able to happen by a combination all of them
Discover omissions and ambiguities in specifications
• Disadvantages:
If we have a lot of combinations, it may not be possible or sensible to test
every combination
If we are time-constrained, we may not have time to test all combinations.

17. Lesson learn
• Don’t just assume that all combinations need to be tested
• It is always better to prioritize and test the most important
combinations.
• Having the full table helps us to decide which combinations we
should test and which not to test this time.