BLACK B0X TESTING AND WHITE BOX TESTING IN SOFTWARE ENGINEERING
BLACK Box TESTING
It is defined as a testing technique in which functionality of
the Application Under Test (AUT) is tested without looking at
the internal code structure, implementation details and
knowledge of internal paths of the software.
This type of testing is based entirely on software requirements
and specifications.
It is focus on inputs and output of the software system
without bothering about internal knowledge of the software
program.
Input Output
Black Box 2
BLACK B0X TESTING AND WHITE BOX TESTING IN SOFTWARE ENGINEERING
>The above Black-Box can be any software system youwant to
test.
> For Example, an operating system like Windows, a website
like Google, a database like Oracle or even your own custom
application.
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BLACK B0X TESTING AND WHTE BOX TESTING IN SOFTWARE ENGINEERING
Steps Involved In Black Box Testing:
1 Initially, the requirements and specifications of the system are
examined.
2. Tester chooses valid inputs (positive test scenario) to check
whether SUT processes them correctly. Also, some invalid inputs
(negative test scenario) are chosen to verify that the SUT is able to
detect them.
3
Tester determines expected outputs for all those inputs.
4 Software tester constructs test cases with the selected inputs.
5 The test cases are executed.
6. Software tester compares the actual outputs vith the expected
outputs.
4
7. Defects if any are fixed and re-tested.
BLACK B0X TESTING AND WHITE BOX TESTING IN SOFTWARE ENGINEERING
Types of Black Box Testing
1. Functional testing - This black box testing type is related to the
functional requirements of a system; it is done by software testers.
2. Non-functional testing - This type of black box testing is not
related to testing of specific functionality, but non-functional
requirements such as performance, scalability, usability.
3. Regression testing - Regression Testing is done after code fixes,
upgrades or any other system maintenance to check the new code
has not affected the existing code.
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BLACKB0X TESTING AND WHITE BOX TESTING IN SOFTWARE ENGINEERING
Black Box Testing Techniques
1. Equivalence Class Testing:
Equivalence partitioning is a technique of software testing in which
input data is divided into partitions of valid and invalid values.
It helps to reduce the time of testing due to asmaller number of test
cases from infinite to finite.
º It is applicable at all levels of the testing process.
Example: 0TP Number =6 digits
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BLACK B0X TESTING AND WHITE BOX TESTING IN SOFTWARE ENGINEERING
Example: OTP Number =6 digits
Enter OTP Number INVALID INVALID VALID VALID
1Test case 2Test case 3Test case
Enter Six Diglt 0TP Number
DIGITS >=7 DIGITS<=5 DIGITS =6 DIGITS =6
Back Submit 93847262 9845 456234 451483
BLACK B0X TESTING AND WHITE BOX TESTING IN SOFTWARE ENGINEERING
2.Boundary Value Testing:
Boundary value testing is focused on the values at boundaries.
This technique determines whether a certain range of values are
acceptable by the system or not.
º It is very useful in reducing the number of test cases.
It is most suitable for the systems where an input is within certain
ranges.
BLACK BOX TESTING AND WHITE BOX TESTING IN SOFTWARE ENGINEERING
Example for Boundary Value Testing
Nane Enter Your Name
Between 18 to 30
Age
Adhar Number of 12 Digits
Address Enter Your Address
12 14 15 16 17 18 20 22 24 25 26 28 30 31 32 34 36 38 40
-
Invalid Partition Valid Partition Invalid Partition
Invalid test cases Valid test cases Invalid test cases
11, 13, 14, 15, 16, 17 18, 19, 24, 27, 28, 3O 31, 32, 36, 37, 38, 39
BLACK B0X TESTING AND WHITE BOX TESTING IN SOFTWARE ENGINEERING
3. Decision Table Testing:
This is a systematic approach where various input combinations and
their respective system behavior are captured in a tabular form.
It is also known as a cause-effect table.
o This technique is used to pick the test cases in a systematic manner.
o It saves the testing time and gives good coverage to the testing area
of the software application.
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BLACK B0X TESTING AND WHTE BOX TESTING IN SOFTWARE ENGINEERING
Example for Decision Table Testing:
Email (condition1) T F F
Password (condition2) T F T F
Expected Result (Action) Account Page Incorrect password| Incorrect |Incorrect email
email
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BLACK B0X TESTING AND WHITE BOX TESTING IN SOFTWARE ENGINEERING
WHITE BOx TESTING
White box testing is also known as Clear Box testing, Open
Box testing, Structural testing, Transparent Box testing, Code
Based testing, and Glass Box testing.
The primary goal of white box testing is to focus on the flow
of inputs and outputs through the software and strengthening
the security of the software.
Test Case
Input Application Code
Test Case
Output
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BLACK B0X TESTING AND WHTE BOX TESTING IN SOFTWARE ENGINEERING
White Box Testing Techniques:
1.Statement Coverage
º In this technique, the aim is to traverse all statements at least
once. Hence, each line of code is tested.
In the case of a flowchart, every node must be traversed at
least once. Since all lines of code are covered, it helps in
pointing out faulty code.
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BLACK B0X TESTING AND WHITE BOX TESTING IN SOFTWARE ENGINEERING
2. Branch Coverage:
In this technique, test cases are designed so that each branch
from all decision points is traversed at least once.
In a flowchart, alledges must be traversed at least once.
Tent
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BLACK B0X TESTING AND WHITE BOX TESTING IN SOFTWARE ENGINEERING
3. Condition Coverage
In this technique, all individual conditions must be covered as
shown in the following example:
READ X, Y
IF(X ==0||Y =0)
PRINT 0
#TCI -X = 0, Y = 55
#TC2-X=5, Y =0
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BLACK-B0X TESTING AND WHITE BOX TESTING IN SOFTWARE ENGINEERING
4. Multiple Condition Coverage
º In this technique, all the possible combinations of the possible
outcomes of conditions are tested at least once. Let's consider
the following example:
READ X, Y
IF(X ==0|| Y =0)
PRINT 0
#TC1: X=0, Y =0
#TC2: X=0, Y =5
#TC3: X=55, Y =0
#TC4: X= 55, Y = 5
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BLACK B0X TESTING AND WHITE BOX TESTING IN SOFTWARE ENGINEERING
Difference between white-box testing and
black-box testing
White-box testing Black box testing
The developers can perform white The test engineers perform the
box testing. black box testing.
To perform WBT, weshould have To perform BBT, there is no need
an understanding of the to have an understanding of the
progranming languages. programming languages.
In this, we will look into the source In this, we will verify the
code and test the logic of the code. functionality of the application
based on the requirement
specification.
In this, the developer should know In this, there is no need to know
about the internal design of the about the internal design of the 20
code. code.
