Boundary Value Analysis is a category under input domain 
testing which is a kind of functional testing.
Using BVA we can test hw the AUT behaves at their 
boundaries.That is u test the functionality by giving 
inputs at their boundaries : Eg : if test box can accept a 
character string of length 2-8 then your BVA would be, 
i. i/p :2= pass
ii. i/p : 2-1 = Fail
iii. i/p : value btn 3-7 , any one value - Pass
iv. i/p : 8 = pass
v. i/p 8+1 = Fail

if X is the limit you will check values at X-1, X and X+1

BVA is a testcase design technique where we consider the 
boundry values of input and output data.

Boundary value Analysis:It is a technique for test data 
selection.A test engineer choose values that lie along data 
extreme.Boundary values include maximum,minimum,just inside 
boundaries,just outside boundaries,typical values,and error 
values.the expectation is that,if a system works correctly 
for these extreme or special values,then it will  work 
correctly for all values in between.
Eg:if a text box is supposed to accept values in range 1 to 
100,then try providing the following values:
1)1,100 values between 1 and 100 on sampling basis
2)0,101
3)negative values,
4)extremely large values.

When even the test engg need to develop the testcases
for a range kind of input then they will go for BVA
 in this they will concentrate on the boundarys of the range
ex:-
write a test case for email text box
1.it should acccept min 4char & max 20char
usually they will consider the following values
LB-1 LB LB+1 MB UB-1 UB UB+1
3     4 5    12 19 20    21

A technique that consists of developing test cases and 
data, that focus on the input and output boundaries of a 
given function

BVA meant for boundary value analysis is a test designing 
technique is applicable for object testing. To verify the 
max., min.,range lies between max and min size , BVA 
techniqueis used. It is one of relevant tech. to verify the 
length of object instead of going through all one by one 
value testing..let one object having rangr from 1 to 100.
BVA process would be like this .
min value=1=pass
min-1=0=fail
max=100=pass
max+1=101=fail
max-1=99=pass
min+1=2=pass

if any wrong plz, reach to me mail 
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