Definition

Testing conducted to evaluate a system or component in its operational environment or an exact copy of the environment if the environment is in use with the live system.

[Source: BCS+]

Comment

For any business critical system, operational testing should always take place. However, this type of testing is often difficult to fit into the development and testing lifecycle, as operational environment not available until very near the live date. It also may not be cost-effective or timely to conduct this type of test prior to going live.