# Black Box Testing Technique

If I would like to execute**testing a software**(testing web or windows application), I start with thinking about how to select the test cases. If I have no idea about software's internal algorithm and cannot cover all combinations of input values and preconditions for a module of software because of resource constraint (Time or manpower), I will use Black Box Testing Technique to design the input values.

# Boundary value analysis

Boundary value analysis is a software testing technique that selects the input data which represents boundary values. These data includes both boundary and each side of boundary which should be in the smallest increment.**Example**

I would like to test withdrawal on ATM system. The maximum amount is $500 and minimum amount is $1.

Find boundary value:

- Maximum value is $500
- Minimum value is $1

Find each side of boundary value

- $501 and $499 for "Maximum value is $500" case
- $2 and $0 for "Maximum value is $1" case

The final list of input values are

- $501, $499 and $500
- $2, $0 and $1

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Now you can design and execute

**testing a software**(testing web or windows application) by using Boundary value analysis testing technique.Let's find the pairwise testing (All-pairs testing) technique in the next article.

## 2 ความคิดเห็น:

Thanks for the article.Here is one more example on this:Test cases for input box which accepts numbers between 1 and 100 using Boundary value analysis:Test cases with test data exactly as the input boundaries of input domain i.e. values 1 and 100 in our case.Test data with values just below the extreme edges of input domains i.e. values 0 and 99.Test data with values just above the extreme edges of input domain i.e. values 2 and 101.

For more examples visit 5 Boundary Value Analysis Examples

Thanks Dav

Hello,

The Article on black box technique is nice give detail information about it.It's amazing to know about it.Software Testing Services

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