Boundary Value Analysis and Equivalence Partitioning

Hi, This is my first post in Manual Testing and I'm gonna explain you how Boundary Value Analysis and Equivalence Partitioning work.

 Boundary Value Analysis: Basically BVA is a test case desgin technique and also blackbox technique used to test boundary values of the input data and using this technuique we can derive test cases for particluar input data.

example: Consider a textbox which accepts numbers 10-100 then using BVA technique we can take boundry values of data as follows.
 9,10,11,99,100,101 so we can write six test cases for that textbox.

Testcase1: Enter number '9' in the textbox.
Testcase2: Enter number '10' in the textbox.
Testcase3: Enter number '11' in the textbox.
Testcase4: Enter number '99' in the textbox.
Testcase5: Enter number '100' in the textbox.
Testcase6: Enter number '101' in the textbox.

Equivalence Partitioning: This is also test case design technique which divides inputs into different classes and takes one value from each class and basically this technique is used when we know the input range.

example: I'm taking same example of BVA here too, consider a textbox which accepts numbers 10-100 then using this technique we can divide the input as shown below.

                 less than 10   |   10 - 100  | more than 100
                     Class1             Class2            Class3

As you can see i have divided inputs in three different classes and I'm gonna take one value from each of these 3 classes so my test cases are as follows.

Testcase1: Enter any number less than 10.
Testcase2: Enter number between 10-100.
Testcase3:Enter any number more than 100.

So this is how BVA and EP work, i hope this post will clear your doubts about BVA and EP..:)