GMP guidelines require that IT systems must be validated by adequate and documented testing. It is required in all regulated industries: pharmaceuticals, medical devices, food and beverages, cosmetics.
GMP Requirements - “The software development process should be sufficiently well planned, controlled, and documented to detect and correct unexpected results from software changes."
Validation is defined as the documented act of demonstrating that a procedure, process, and activity will consistently lead to the expected results. This is the formal testing to demonstrate that the software meets its specified requirements.