Black Box Testing: Types and techniques of BBT

I have covered what is White box Testing in previous article. Here I will concentrate on Black box testing. BBT advantages, disadvantages and and How Black box testing is performed i.e the black box testing techniques.

Black box testing treats the system as a “black-box”, so it doesn’t explicitly use Knowledge of the internal structure or code. Or in other words the Test engineer need not know the internal working of the “Black box” or application.

Main focus in black box testing is on functionality of the system as a whole. The term ‘behavioral testing’ is also used for black box testing and white box testing is also sometimes called ‘structural testing’. Behavioral test design is slightly different from black-box test design because the use of internal knowledge isn’t strictly forbidden, but it’s still discouraged.

Each testing method has its own advantages and disadvantages. There are some bugs that cannot be found using only black box or only white box. Majority of the applicationa are tested by black box testing method. We need to cover majority of test cases so that most of the bugs will get discovered by blackbox testing.

Black box testing occurs throughout the software development and Testing life cycle i.e in Unit, Integration, System, Acceptance and regression testing stages.

Tools used for Black Box testing:
Black box testing tools are mainly record and playback tools. These tools are used for regression testing that to check whether new build has created any bug in previous working application functionality. These record and playback tools records test cases in the form of some scripts like TSL, VB script, Java script, Perl.

Advantages of Black Box Testing
– Tester can be non-technical.
– Used to verify contradictions in actual system and the specifications.
– Test cases can be designed as soon as the functional specifications are complete

Disadvantages of Black Box Testing
– The test inputs needs to be from large sample space.
– It is difficult to identify all possible inputs in limited testing time. So writing test cases is slow and difficult
– Chances of having unidentified paths during this testing

Methods of Black box Testing:

Graph Based Testing Methods:
Each and every application is build up of some objects. All such objects are identified and graph is prepared. From this object graph each object relationship is identified and test cases written accordingly to discover the errors.

Error Guessing:
This is purely based on previous experience and judgment of tester. Error Guessing is the art of guessing where errors can be hidden. For this technique there are no specific tools, writing the test cases that cover all the application paths.

Boundary Value Analysis:
Many systems have tendency to fail on boundary. So testing boundry values of application is important. Boundary Value Analysis (BVA) is a test Functional Testing technique where the extreme boundary values are chosen. Boundary values include maximum, minimum, just inside/outside boundaries, typical values, and error values.

------------

Extends equivalence partitioning
Test both sides of each boundary
Look at output boundaries for test cases too
Test min, min-1, max, max+1, typical values

BVA techniques:
1. Number of variables
For n variables: BVA yields 4n + 1 test cases.
2. Kinds of ranges
Generalizing ranges depends on the nature or type of variables
Advantages of Boundary Value Analysis
1. Robustness Testing – Boundary Value Analysis plus values that go beyond the limits
2. Min – 1, Min, Min +1, Nom, Max -1, Max, Max +1
3. Forces attention to exception handling

Limitations of Boundary Value Analysis
Boundary value testing is efficient only for variables of fixed values i.e boundary.

Equivalence Partitioning:
Equivalence partitioning is a black box testing method that divides the input domain of a program into classes of data from which test cases can be derived.

How is this partitioning performed while testing:
1. If an input condition specifies a range, one valid and one two invalid classes are defined.
2. If an input condition requires a specific value, one valid and two invalid equivalence classes are defined.
3. If an input condition specifies a member of a set, one valid and one invalid equivalence class is defined.
4. If an input condition is Boolean, one valid and one invalid class is defined.

Comparison Testing:
Different independent versions of same software are used to compare to each other for testing in this method.

Reference- http://www.softrel.org/stgb.html



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129 comments ↓

#1 namita on 08.10.07 at 4:23 am

it was good and valuable information about the basics of BBT.

#2 Vijay on 08.10.07 at 5:29 am

Thanks Namita
Actually you could have observed that most of the testers in India are Black box testers. There is need to give more emphasis on this topic. So I will keep writing some more topics on Black box testing and practical methods.

#3 Priya on 08.10.07 at 9:14 am

Need to know about the check list cases

#4 Zalak on 08.11.07 at 4:55 am

Really ! You have very good skill of representing this !
I want to read more and more about testing through this blog….

Thanks

#5 saranya on 08.11.07 at 5:00 am

its really good to know the basics in blackbox testing..thanks.please do emphasize on templates.

#6 Shridhar on 08.14.07 at 6:34 am

Comments are Excellent . I love to see such many and More Comments.

Thanks
Shridhar

#7 shaji on 09.16.07 at 1:15 pm

can u provide me with blackbox testing interview questions?

#8 P Rajkumar on 09.24.07 at 5:27 am

dear all,

can u tell me what is a build? when it is started ?

bye
raj

#9 P Rajkumar on 09.24.07 at 5:30 am

can we test the application without having any system this question was asked in interview.And also how to generate the reports.pls suggests me

regards
raj

#10 Kharananda on 09.27.07 at 10:20 am

Priya, i will send u notes about the check list cases if u leave ur mail id and Phone no

#11 Rajani on 11.19.07 at 6:24 am

what is prototype testing?

#12 JaiPrakash on 11.19.07 at 2:03 pm

What is white box testing ?

#13 Sowmya on 11.23.07 at 7:13 am

White box testing is based on knowledge of the internal logic of an application’s code. Also known as Glass box Testing. Internal software and code working should be known for this type of testing. Tests are based on coverage of code statements, branches, paths, conditions.

#14 Tulsi Akula on 11.23.07 at 7:14 am

what do u mean by framework?

#15 sweta on 12.13.07 at 6:12 am

wat do u mean by checklists in testing?

#16 Varsha on 12.17.07 at 10:14 am

Hi Vijay

Recently I came across the foll. terms:

Grey Box testing
Red Box testing
Yellow Box testing &
Green Box testing

Could u pls explain the above types of testing in detail. Thanks.

#17 nidhi on 01.21.08 at 9:10 am

hi vijay

plz tell something more about black box testing

thanks

#18 Sivaguru on 02.08.08 at 8:06 am

1.What is the Difference Between Test Cases and Test Scenarios????????

2. Canu plz tell me the exacr definition of Test Scenario??

#19 Kittu on 02.25.08 at 4:27 am

hi Rajani,

a prototype testing is a sample application without Functionality.

#20 Kittu on 02.25.08 at 4:35 am

hi sivaguru,

test Scenario specifies required test conditions to apply on a build.
where as test case specifies detailed procedure to apply the test conditions on a build.

This is the best answer that i can give…….

#21 prasanna on 03.01.08 at 6:44 am

Hi all,

Any sample testcases for implementing the “Graphs based testing Methods???

#22 selvam on 03.05.08 at 12:16 pm

Articles and comments brings me often to this site.

great.

#23 abhas on 03.06.08 at 3:42 am

plz send me links of technical papers on black box testing if anybody know before sunday my email address is
abhasgoyal@gmail.com

#24 Pavitra on 03.06.08 at 4:12 am

I want to learn about test cases and how to write testcases for database testing and system testing

#25 vishal chinchane on 03.13.08 at 6:21 am

what is Posittive test case & negetive test case?

#26 srikanth on 03.28.08 at 2:22 pm

hello to everyone, i want to know the basic concepts of testing tools in brief individually, can u people let me know from where can i get this information

thank u

#27 pratap on 03.31.08 at 4:33 am

whaT IS SMOKE TESTING , SANITY TESTING

#28 mahamaya on 04.19.08 at 7:28 am

How we can plot a graph between test conditions and test cases in black-box testing?

#29 Vijay on 04.24.08 at 11:29 am

@ varsha, bala
“”Red Box testing
Yellow Box testing &
Green Box testing””,
there is no terminology like this in testing industry, some can say it is protocol testing-redbox, or error message testing-red box, warning message testing-yellow box and green box- environmental testing, of cource white, black, grey box testing is there. Or else why it is called by red, green, yellow box testing, anyway it is not due to the icon\symbol present in the warning or error messages.

Vijay

#30 bubu on 05.03.08 at 9:05 am

hey guys, trull i learn a lot from u. …thanks

Can anyone explain to be more in details. wat is error guessing?

thankx

#31 Saurav on 06.02.08 at 7:54 pm

It is a nice presentation as well as very simple to understand.
please, keep on upgrading.

#32 rashmi on 07.08.08 at 6:09 am

Hi,
I want to know what exactly do the term exhaustive testing ? IS it possible to carry it out ?

Thanks,
Rashmi

#33 suresh on 07.17.08 at 5:19 am

hey guys, trully i learnt a lot from u. …thanks

Can anyone explain more in details. ….. Tools in Black Box Testing

#34 suresh bandiwaddar on 07.17.08 at 5:24 am

can any body explain testing tools in black box testing

#35 Rishi on 08.04.08 at 4:39 pm

wat abt comparison of different testing technique??

#36 Kranthi on 08.23.08 at 4:36 pm

Iam a fresher in testing field. Now I’m testing a web based application. I want to know what all procedures( in WBT & BBT) I hav to do for a successful test.

Mail ID: Tammukchowdary@gmail.com

#37 vivek on 10.18.08 at 5:52 am

Diffrence between black box and white box testing?

#38 sreesree on 10.20.08 at 10:26 am

wat r d levels of black box testing?

#39 nodeen on 11.04.08 at 7:19 am

Hi Vijay,

Currently, I’m working on a functional test cases document. But I’m having difficulty in determine which of my user requirement is consider to be a functional requirement and which are non-functional. For example, one of the requirements said that the system should be able to send the request to dedicated travel agent and the other requirements said that the system should be able to convert monthly report into a .csv format. Do you think those 2 requirements consider as functional requirement? Anyone can help?.

#40 deji on 11.08.08 at 4:15 am

Hi Nodeen,

It seems we have similar projects at hand and I am wondering if you would be happy to share your experience on the forum. My task is to review lines of code for inherent vulnerabilities using black-box testing. kindly holler asap

#41 Anagha on 12.23.08 at 8:45 am

This was helpfull.. Thanx.

#42 Abhirup on 01.02.09 at 8:40 am

Would manual testing can enhance my career?

#43 Priya on 01.05.09 at 11:49 am

Hi
what is system integration testing??

#44 Pankaj on 01.05.09 at 12:54 pm

@Abhirup
Manual Testing is as good as any other testing skills. Its just the level of specilization that matters. I’ve seen many manual functional testers went on to become Business Analysts and further more. So if you are interested in testing (be it manual), just put great efforts and you will achive great results.

#45 Abhi on 02.12.09 at 7:06 am

Hi,

Really nice to read the article.

Generally we develop the Test Plan in a xl sheet with diff. info. in different Tabs.

Can u provide me a Standard Test Plan including all diff. types of info. !! It will be vey helpful for me….

Thanks

A. Adhikary

#46 k.pradeepika on 03.29.09 at 3:50 am

this black box testings can b read from s.e pressman edition software engg, try it;

its also really good;

#47 gurpreet kaur on 04.02.09 at 7:44 am

hello
I m doing thesis on black box testing.what r problems occured in black box testing. plz send me some important links that can help me in my thesis

#48 Brendon Buthello on 05.12.09 at 9:43 am

Hi,
What a comprehensive article on Black Box Testing! It was thoroughly enlightening too! Fantastic work, sir!

I have known only Indusa Infotech to be doing these services in Ahmedabad. Can you name some more companies in Ahmedabad which offer black box testing services..

Thanks again for the insight

#49 kalpana on 05.26.09 at 11:42 pm

Hi
where do you derive the inputs for Black Box testing?
please answer this question(asked in interview)

Thanks

#50 sundar on 06.17.09 at 10:09 am

i am testing java application by using jmeter testing tool.
i had prepared functional test test case summary report.now i want to prepare load test report. please any one give some idea how to prepare load test report.
mail: sunaruna84@gmail.com
with regards
sundar

#51 cooldude on 07.20.09 at 2:12 pm

Can smbdy explain in detail what is red box testing?

Wiki Ans:red box testing is used to test products on hardware devices, networking components like protocolss

Vijay says(Host):it is protocol testing-redbox, or error message testing-red box.

Can some one clarifies these ans..?

#52 Prasad on 07.26.09 at 8:31 am

@ cool dude,

vijay is correct. in red-box testing u have to test the protocol & Error messages.

#53 Prasad on 07.26.09 at 8:33 am

@ kalpana #49,

inputs will be given as per the Business requirement.
so the inputs are not standard depends on the business requirment.

#54 shivakumar kolkar on 08.05.09 at 1:29 pm

Hi vijay,
Its a nice documnet.

It would be good if you divide the testing types in functional and non-functional.

As a testing beginner …..people want to know the basics ….

Thanks
Shiva

#55 evi on 08.24.09 at 8:10 pm

what are different QA methodologies

#56 STORM on 11.04.09 at 6:49 am

Hi Pal

In this module u use the UNIT testing as the part of BLACK BOX TESTING.
Is this correct?

#57 Vimal Bhatnagar on 12.07.09 at 8:46 am

Hi Praveen,

Please suggest me which book i purchase and how to start this cource initially.

#58 Vimal Bhatnagar on 12.07.09 at 8:49 am

Please giv me Our contact no.I need a suggestion.
My Mob.No.Is 9953178623

#59 Anitha on 01.11.10 at 1:48 pm

Can anybody explain about ‘0’ Functionality testing

#60 vignesh on 02.07.10 at 1:29 pm

the website is very useful for me thak u

#61 D Raja Sekhar on 02.09.10 at 3:43 am

i love u so much who had written this………………….its really gooooooooooood

#62 Akbar Hussain on 02.13.10 at 4:08 am

Types of FRAME WORK IN TESTING

The Test Script Modularity Framework

The test script modularity framework requires the creation of small, independent scripts that represent modules, sections, and functions of the application-under-test. These small scripts are then used in a hierarchical fashion to construct larger tests, realizing a particular test case.

Of all the frameworks I’ll review, this one should be the simplest to grasp and master. It’s a well-known programming strategy to build an abstraction layer in front of a component to hide the component from the rest of the application. This insulates the application from modifications in the component and provides modularity in the application design. The test script modularity framework applies this principle of abstraction or encapsulation in order to improve the maintainability and scalability of automated test suites.

To demonstrate the use of this framework, I’ll automate a simple test case for the Windows Calculator program (see Figure 1) to test the basic functions (add, subtract, divide, and multiply).

The Test Script Modularity Framework

The test script modularity framework requires the creation of small, independent scripts that represent modules, sections, and functions of the application-under-test. These small scripts are then used in a hierarchical fashion to construct larger tests, realizing a particular test case.

Of all the frameworks I’ll review, this one should be the simplest to grasp and master. It’s a well-known programming strategy to build an abstraction layer in front of a component to hide the component from the rest of the application. This insulates the application from modifications in the component and provides modularity in the application design. The test script modularity framework applies this principle of abstraction or encapsulation in order to improve the maintainability and scalability of automated test suites.

To demonstrate the use of this framework, I’ll automate a simple test case for the Windows Calculator program (see Figure 1) to test the basic functions (add, subtract, divide, and multiply).

The Keyword-Driven or Table-Driven Testing Framework

Keyword-driven testing and table-driven testing are interchangeable terms that refer to an application-independent automation framework. This framework requires the development of data tables and keywords, independent of the test automation tool used to execute them and the test script code that “drives” the application-under-test and the data. Keyword-driven tests look very similar to manual test cases. In a keyword-driven test, the functionality of the application-under-test is documented in a table as well as in step-by-step instructions for each test.

If we were to map out the actions we perform with the mouse when we test our Windows Calculator functions by hand, we could create the following table. The “Window” column contains the name of the application window where we’re performing the mouse action (in this case, they all happen to be in the Calculator window). The “Control” column names the type of control the mouse is clicking. The “Action” column lists the action taken with the mouse (or by the tester). And the “Arguments” column names a specific control (1, 2, 3, 5, +, -, and so on).

For Further details Contact akbar.shaik@yahoo.com
Hyderabad

#63 Gavaskar on 03.05.10 at 4:49 am

Hi vijay,

excellant job yours… thanks

i need a exact answere for two question..

1.Define Defect Density?
2.What are the techniques used to write a test case?

#64 Alam khan on 03.22.10 at 6:03 pm

i am a grasduate and i am really confused to step into testing field coz many graduates told me that it has no scope..Since black box testing does not involve internal functionality of a s/w,so a non-tech guy can also do it,than whats the use of studying engineering or graduating from Information technology..please clear my doubts.Thankyou

#65 mangai on 04.09.10 at 5:25 am

am very new to testing and these information are really excellent………..
Regards
mangai

#66 Gavaskar on 04.09.10 at 6:11 am

Hi,

can any one ans this question plz?

1.Tell me the difference between test matrix & test metrix
2.Explain Schedule variance, effort variance, size variance, requirement stablility index

#67 Jayaprakash on 04.14.10 at 12:16 pm

Article on BBT is very good… Want to know Examples for 4 points mentioned in ” How is this partitioning performing while testing, this will be more helpful to get much more idea on Equivalence partitioning technique.

Thanks
jayaprakash

#68 geet on 04.16.10 at 8:40 am

something is still missing….
for proper explaination of bbt… plx explain bbt types with proper examples

#69 gowtham on 04.17.10 at 3:14 pm

it is not nessesary to write exam but it is used to know whatis it

#70 Praveenkumar on 04.18.10 at 2:23 pm

Thanks its very useful to understand the extract concept,,,

#71 jyoti singh on 05.10.10 at 2:12 pm

What is REGRATION testing?

#72 ramesh on 05.10.10 at 2:33 pm

no comments

#73 Priyanka on 05.28.10 at 8:20 am

Thanks for the valuable information about BVA..

#74 Mayasen on 05.28.10 at 8:55 am

Hi Vijay,

Clear road; you made a nice way to walk through Testing Types and Techniques.

Wishes…!!! :)

#75 Sudheer on 05.31.10 at 7:31 am

Hi,

The article on BBT is really so nice.This gives an Idea for the beginners.

#76 Dipak dash on 06.06.10 at 2:57 pm

can u people provide me the FAQ OF BLACK BOX TESTING

#77 chandraketu prasad on 06.14.10 at 6:58 am

the data provided are valuable and helped me in making my presentataion.can u people provide me a complete ppt of software testing????

#78 Ahmad A on 06.17.10 at 3:28 pm

Dear All,

I am a masters student and my thesis about black box testing, the problem that I could not make a list by all the tests techniques under black box testing, different books different name, basically the same test but different name, and as well different companies different names, I need to make a list about them, so maybe anyone can help me here…

thanks,
Ahmad A

#79 neha on 08.08.10 at 8:25 am

this answer is very helpful to create my assignment..
thanks dear

#80 kalaranjani on 08.25.10 at 10:13 am

plz,give me more details about blockbox testing

#81 Pawan Rai on 09.26.10 at 2:11 pm

hi, everybody
could anyone explain, how can we measure the height of kutubminar without using any measuring instrument.

#82 anu on 10.21.10 at 4:52 pm

hiiiiiii can u tell me hw to map white box n black testing plz
…………….

#83 jitendra singh on 10.26.10 at 6:06 am

@ varsha, bala
“”Red Box testing
Yellow Box testing &
Green Box testing””,
there is no terminology like this in testing industry, some can say it is protocol testing-redbox, or error message testing-red box, warning message testing-yellow box and green box- environmental testing, of cource white, black, grey box testing is there. Or else why it is called by red, green, yellow box testing, anyway it is not due to the icon\symbol present in the warning or error messages.

#84 harshad on 11.16.10 at 7:34 am

Actually you could have observed that most of the testers in India are Black box testers. There is need to give more emphasis on this topic. So I will keep writing some more topics on Black box testing and practical methods.

#85 sravan chowdary on 12.15.10 at 8:42 am

it was good and valuable information about the basics of BBT.

#86 muzk on 01.06.11 at 6:18 am

pls clear my concept on static and dynamic testing

#87 sajan on 01.30.11 at 11:47 am

hey cn u jst provide me a proper example of black box testin

#88 sajan on 01.30.11 at 11:49 am

hey cn u jst provide me a proper example of black box testin
… ????????

#89 Nandhakumar on 02.08.11 at 8:24 am

ya, not bad, but i need to get exact particulars for what i’m searching?

#90 isha on 02.20.11 at 3:51 pm

Thanks its very useful ….but i need more details with examples

#91 shailaja on 02.27.11 at 5:01 pm

Informative article…would like to know are the above testing techniques are effective for product based companies

#92 amaresh on 03.09.11 at 5:53 pm

will you confirm on RED BOX TESTING, YELLOW BOX TESTING and GREEN BOX TESTING

#93 Aditya Pant on 05.29.11 at 11:34 am

hi frnds…i just want to know that right now i am just a beginner in testing field…but i want to persue my carrer in testing and i wanna know frm where to start and study material…..i am in level 1 i.e justa a beginner….Plz help

#94 Raul on 06.02.11 at 12:50 pm

hi,

there are many jobs testing field . also big package ….

#95 Thinking Out of the Box While Testing Software! — Software Testing Help on 07.04.11 at 6:18 pm

[...] taught or we learn are the Two Boxes, a white box and a black box. Since then all we do is either black box or white box testing. This has limited our mind from thinking beyond the boxes. Did we ever think [...]

#96 Prajakta on 07.25.11 at 2:18 pm

Hi,
what is prototype Testing ? Difference Between Black Box Testing & White Box Testing?

#97 bharathi on 08.01.11 at 7:06 am

hi
i want about standard methodology in testing i knw something but i have more about that one.plz give me reply

#98 akshit on 08.05.11 at 6:35 pm

wao gr8 …..awsm keep it up dude..passed my internal exams with notes of ur’s on bbt ..keep it up keep on going lyk this

#99 Application Testing – Into the Basics of Software Testing! — Software Testing Help on 08.15.11 at 8:11 pm

[...] Black Box: In black-box testing, the AUT is validated against its requirements considering the inputs and [...]

#100 eswaran k on 08.25.11 at 4:59 pm

Block box testing:
~ no knowledge logic of an internal logic code or code required
~test are based on only requirement and function

#101 eswaran k on 08.25.11 at 5:02 pm

block box:
~no knowledge of an programing lanuage only requirement and function

#102 eswaran k on 08.27.11 at 7:19 am

*no knowledge of an internal design code.
*only functions and requirement

#103 vaneet on 09.15.11 at 8:12 am

awesome yrr……. ite really helped me out….

vaneetbhasin@gmail.com

#104 subbu on 09.21.11 at 6:26 am

nice to understand the black box testing technics

#105 SUJITH on 09.29.11 at 10:13 am

NICE Example 4 Black Box Testing.

#106 Sharjeel on 10.24.11 at 10:06 pm

nice sharing ……….

#107 ashif ali on 01.16.12 at 4:20 am

Desertation Topic: Designing and boundary value analysis (using Black Box Testing).
Abstract:
Black box testing treats the system as a “black-box”, so it doesn’t explicitly use Knowledge of the internal structure or code. Or in other words the Test engineer need not know the internal working of the “Black box” or application.
Main focus in black box testing is on functionality of the system as a whole. The term ‘behavioral testing’ is also used for black box testing and white box testing is also sometimes called ‘structural testing’. Behavioral test design is slightly different from black-box test design because the use of internal knowledge isn’t strictly forbidden, but it’s still discouraged.
Each testing method has its own advantages and disadvantages. There are some bugs that cannot be found using only black box or only white box. Majority of the applicationa are tested by black box testing method. We need to cover majority of test cases so that most of the bugs will get discovered by blackbox testing.
Black box testing occurs throughout the software development and Testing life cycle i.e in Unit, Integration, System, Acceptance and regression testing stages.
Tools used for Black Box testing:

Black box testing tools are mainly record and playback tools. These tools are used for regression testing that to check whether new build has created any bug in previous working application functionality. These record and playback tools records test cases in the form of some scripts like TSL, VB script, Java script, Perl.

Advantages of Black Box Testing

– Tester can be non-technical.
– Used to verify contradictions in actual system and the specifications.
– Test cases can be designed as soon as the functional specifications are complete

Disadvantages of Black Box Testing

– The test inputs needs to be from large sample space.
– It is difficult to identify all possible inputs in limited testing time. So writing test cases is slow and difficult
– Chances of having unidentified paths during this testing

Methods of Black box Testing:
Graph Based Testing Methods:

Each and every application is build up of some objects. All such objects are identified and graph is prepared. From this object graph each object relationship is identified and test cases written accordingly to discover the errors.
Error Guessing:

This is purely based on previous experience and judgment of tester. Error Guessing is the art of guessing where errors can be hidden. For this technique there are no specific tools, writing the test cases that cover all the application paths.

Boundary Value Analysis:

Many systems have tendency to fail on boundary. So testing boundry values of application is important. Boundary Value Analysis (BVA) is a test Functional Testing technique where the extreme boundary values are chosen. Boundary values include maximum, minimum, just inside/outside boundaries, typical values, and error values.
Extends equivalence partitioning
Test both sides of each boundary
Look at output boundaries for test cases too
Test min, min-1, max, max+1, typical values

BVA techniques:
1. Number of variables
For n variables: BVA yields 4n + 1 test cases.

2. Kinds of ranges
Generalizing ranges depends on the nature or type of variables
Advantages of Boundary Value Analysis
1. Robustness Testing – Boundary Value Analysis plus values that go beyond the limits
2. Min – 1, Min, Min +1, Nom, Max -1, Max, Max +1
3. Forces attention to exception handling

Limitations of Boundary Value Analysis
Boundary value testing is efficient only for variables of fixed values i.e boundary.

Equivalence Partitioning:
Equivalence partitioning is a black box testing method that divides the input domain of a program into classes of data from which test cases can be derived.

How is this partitioning performed while testing:
1. If an input condition specifies a range, one valid and one two invalid classes are defined.
2. If an input condition requires a specific value, one valid and two invalid equivalence classes are defined.
3. If an input condition specifies a member of a set, one valid and one invalid equivalence class is defined.
4. If an input condition is Boolean, one valid and one invalid class is defined.

Comparison Testing:
Different independent versions of same software are used to compare to each other for testing in this method.

Boundary value analysis and Equivalence partitioning, explained with simple example:
Boundary value analysis and equivalence partitioning both are test case design strategies in black box testing.
Equivalence Partitioning:

In this method the input domain data is divided into different equivalence data classes. This method is typically used to reduce the total number of test cases to a finite set of testable test cases, still covering maximum requirements.
In short it is the process of taking all possible test cases and placing them into classes. One test value is picked from each class while testing.

E.g.: If you are testing for an input box accepting numbers from 1 to 1000 then there is no use in writing thousand test cases for all 1000 valid input numbers plus other test cases for invalid data.
Using equivalence partitioning method above test cases can be divided into three sets of input data called as classes. Each test case is a representative of respective class.
So in above example we can divide our test cases into three equivalence classes of some valid and invalid inputs.

Test cases for input box accepting numbers between 1 and 1000 using Equivalence Partitioning:

1) One input data class with all valid inputs. Pick a single value from range 1 to 1000 as a valid test case. If you select other values between 1 and 1000 then result is going to be same. So one test case for valid input data should be sufficient.

2) Input data class with all values below lower limit. I.e. any value below 1, as a invalid input data test case.

3) Input data with any value greater than 1000 to represent third invalid input class.
So using equivalence partitioning you have categorized all possible test cases into three classes.

Test cases with other values from any class should give you the same result.
We have selected one representative from every input class to design our test cases. Test case values are selected in such a way that largest number of attributes of equivalence class can be exercised.
Equivalence partitioning uses fewest test cases to cover maximum requirements.
Boundary value analysis:

It’s widely recognized that input values at the extreme ends of input domain cause more errors in system. More application errors occur at the boundaries of input domain. ‘Boundary value analysis’ testing technique is used to identify errors at boundaries rather than finding those exist in center of input domain.
Boundary value analysis is a next part of Equivalence partitioning for designing test cases where test cases are selected at the edges of the equivalence classes.
Test cases for input box accepting numbers between 1 and 1000 using Boundary value analysis:

1) Test cases with test data exactly as the input boundaries of input domain i.e. values 1 and 1000 in our case.
2) Test data with values just below the extreme edges of input domains i.e. values 0 and 999.
3) Test data with values just above the extreme edges of input domain i.e. values 2 and 1001.
Boundary value analysis is often called as a part of stress and negative testing.
Note: There is no hard-and-fast rule to test only one value from each equivalence class you created for input domains. You can select multiple valid and invalid values from each equivalence class according to your needs and previous judgments.

E.g. if you divided 1 to 1000 input values in valid data equivalence class, then you can select test case values like: 1, 11, 100, 950 etc. Same case for other test cases having invalid data classes.
This should be a very basic and simple example to understand the Boundary value analysis and Equivalence partitioning concept.
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#108 chanchreek ameta on 01.17.12 at 9:14 am

good information

#109 Chinna on 02.22.12 at 7:53 am

Where is the techinques explained here?

#110 jothi on 02.24.12 at 2:14 pm

wat is functional testing types

#111 jothi on 02.24.12 at 2:17 pm

wat is functional testing types and wat do u mean by smoke testing

#112 jazz dhaliwal on 02.25.12 at 12:33 am

it was quite useful information..worked well for me..

#113 sindhu on 03.05.12 at 1:42 pm

its very valuable.And very usefull for my seminar…..

#114 waqas haider on 04.05.12 at 6:08 am

asalam…..:)
nice awsm…its really good to know the basics in blackbox testing and so many other terminologies
thanx 2 all……viki

#115 Deepti Sharma on 05.11.12 at 11:49 am

nice coverage on BBT…especially for a fresher in testing…simple and understandable.

#116 ravi on 06.26.12 at 3:29 pm

what is sdlc and stlc

#117 ravi on 06.26.12 at 3:30 pm

can u explan phases of sdlc and their use

#118 aditi on 06.28.12 at 1:00 pm

Hi Vijay,
Thanks alot for sharing such a good explaination.

can u please send me some ebooks related to testing on my id: saxena.aditi7887@gmail.com

Thanks in advance!!!

#119 Los Angeles web hosting on 10.16.12 at 12:14 pm

Nice Explantion..Thanks a lot..

#120 karthika on 11.17.12 at 2:10 pm

what is object testing ?

#121 Manthan on 12.24.12 at 10:26 am

If any company is hiwring me for the job of black box testing then can i change it to WBT???

#122 shashmitha on 02.24.13 at 2:42 am

Hi Varsha,(#16)

I jus want to share my knowledge abt yellow and green box testing.
YELLOW BOX : Yellow box is a testing technique for acceptance testing. Alpha and Beta tests together is called as Yellow box testing technique.
Product based acceptance testing is called as Alpha test and Project based acceptance testing is called as Beta test.

GREEN BOX TESTING TECHNIQUE: This is related to the s/w release or delivery. “Delivery team” will go the customer site, install the s/w, and observe various factors as below mentioned:
1. Complete installation of s/w
2. Overall functionality
3. Input devices handling
4. Output devices handling
5. Secondary storage devices handling
6. OS support
7. Co-existence with other s/w
The above observations at the customer site are called as Green Box Testing Technique.

#123 radhika on 03.20.13 at 6:27 am

can u tell me which type of questions ,i have to face in blockbox testers interview? plz help me.. i am a beginner

#124 Somesh Pathare on 06.03.13 at 9:59 am

These Articles are very good.
But i want to
1.Test Case Template for Web Application.
2.How to write test cases for Black box and White Box Testing.

#125 Abhishek on 07.25.13 at 10:37 am

good explanation

you can find another interesting article on

http://blogs.tutorialshouse.com/black-box-testing/

#126 setefano funaki on 10.24.13 at 9:03 pm

what is a benefit of blackbox tester. help me please im just a fool

#127 setefano funaki on 10.24.13 at 9:05 pm

what is a shortcomings of black box testing. please help me

#128 Senthilnathan on 11.08.13 at 9:34 am

Hi –
Pl share me more details on Graph based tests.
If possible, share me with examples. Thanks.

#129 Aparna on 02.26.14 at 7:50 pm

I am looking for some live project with the test cases.If anybody can be nice enough to send them.my email is akulk2000@yahoo.com