# Boundary Value Analysis in software testing with Example

What is Boundary Value analysis  (BVA)

Boundary value analysis is a (software testing) black box Testing technique or specification based testing technique . This Technique is used to test the boundary values .It is widely recognized that input values at the extreme ends of the input domain cause more chances of errors in application .
While testing the boundary value analysis the main aim of software tester is to check that application is providing the correct input or not when enter the boundary values.
• Boundary value analysis done after the compilation of Equivalence Partitioning.
• Equivalence class Partitioning play an important role in boundary testing .

 Fig. Boundary value analysis

What is boundary value?
A boundary value are those that contain the limits of variable (Upper and lower ). For Example there is an student registeration page and  age field is there which accept the student age 18 as minimum and 35 as maximum.Here (18 -35) are the boundary value for the field .

How to do Boundary Value Testing?
If the field to be tested accept the range of value from a to b then test field by (a-1, a ,a+1 and b-1, b ,b+1)

 Fig.  Boundary value testing

Example of Boundary Value Analysis

In below student sign up page the boundary value for age field is 18 and 35 let try to understand the real analysis by this example .

 Fig. Boundary value analysis Example

Boundary Value : 18(Minimum) and 35 (maximum)
using (a-1, a ,a+1 and b-1, b ,b+1) formula test engineer have to find the range and on the basis of this they have to write the test cases .
(17 , 18 , 19 and 34 ,35 ,36)

While writing the test cases for boundary value tester have to identify the range boundary value and then start writing test cases .

Example - Test Cases

• Check the age field by entering the value which is not in the range (ie.17and 36)
• Check the age field by entering the exact boundary value (ie . 18and 35 )
• Check the age field by entering the value which is within the boundary value (17 to 34)
The various boundary value analysis advantage are given below
• Boundary value analysis (BVA) technique of testing is very easy to use and remember.
• The overall time taken to execute the test cases are reduced.
• Generation of test cases through BVA are minimal
List of disadvantage of boundary value analysis are given below.
• BVA does not test all possible input.
• BVA does not test test the combination of inputs .

Hope !! The above tutorial of boundary value analysis helpful for You ...
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