Verification and Validation

Verification and Validation are independent procedures that are used together for checking that a product, service, or system meets requirements and specifications and that it fulfills its intended purpose.

In term of software, verification is an inspection or audit without having to run code of the application, while the validation is performed with the actual code execution.

For example, code review and syntax checking is verification, while validation involves software code running and control of test results.

As a general rule validation should be performed after the verification process is executed.

The difference between verification and validation is illustrated in the below figure

 

Verification answers the question "Are we making the product properly?" while validation - "Are we making a proper product?"

An example:

Requirement specification:

User wants to control the lights in 4 rooms by remote command sent from the UI for each room separately.

Functional specification:

The UI will contain 4 checkboxes labelled according to rooms they control.

When a checkbox is checked, the signal is sent to corresponding light. A green dot appears next to the checkbox

When a checkbox is unchecked, the signal (turn off) is sent to corresponding light. A red dot appears next to the checkbox.

 Answer:

Specifications	Verification/ validation
There are supposed to be three switches and two buttons on this wall	Verification
The switches are supposed to be equi-distant apart and 48 inches off the floor	Verification
The buttons are supposed to be on either side of the switches	Verification
The left button is supposed to be labeled "Left"	Verification
The right button is supposed to be labeled "Right"	Verification
If I click the left button on, does it disable the far right switch?	validation
If I click the left buton off, does it enable the far right switch?	validation
If I click the right button on, does it disable the far left switch?	validation
If I click the right button off, does it enable the far left switch?	validation
If I click both buttons on does only the middle switch work?	validation

 
for more detail

http://software.intel.com/en-us/blogs/2010/02/20/verification-and-validation

 

Post#5

Ali Alshaqaq