Black Box Testing Technique

If I would like to execute testing a software (web testing or windows application testing), I start with thinking about how to select the test cases. Then, 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 for this software testing.

Equivalence partitioning

Equivalence partitioning is a software testing technique that groups the input data for a module of a software into partitions of data that can represent each possible case. Then, select an input data from each partition.

Example
I would like to execute software testing with withdrawal module on ATM system. The maximum amount is $500 and minimum amount is $1.

Partitioning:

More than $500
Between $500 and $1
Less than $1

Select input data:

$800 for "More than $500" case
$200 for "Between $500 and $1" case
$0 for "Less than $1" case

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Now you can design and execute testing a software (web testing or windows application testing) by using Equivalence partitioning testing technique.

Let's find the Boundary value analysis testing technique for software testing in the next article.

Posted in: Test Design Technique

3 ความคิดเห็น:

๋Jingjok says:

November 9, 2011 at 3:48 PM

Great post. Thanks a lot.

SamRat Jha. says:

November 15, 2011 at 12:22 PM

Sir,
I have a question here .. Using EP in this above example itself .. Do we write test cases on $1 and $ 500..??

I mean to ask : Between $1 and $500 , Including or Excluding the boundaries..???

I can be reached at samrat.bats@gmail.com

thebobblogs says:

November 15, 2011 at 7:28 PM

Hi SamRat Jha,
It is up to your decision. If you think that the boundary value should be another partition, it can be split like this.
$800 for "More than $500" case
$500 for "Equal to $500" case
$1 for "Equal to $1" case
$200 for "Between $500 and $1" case
$0 for "Less than $1" case

BTW, I usually use follows the example and then, combine this technique with BV as below.
1) EP
$800 for "More than $500" case
$200 for "Between $500 and $1" case
$0 for "Less than $1" case
2) BV
$501, $499 and $500 for "Maximum value is $500" case
$2, $0 and $1 for "Maximum value is $1" case

Let me know if you still have any question.