PURPOSE OQ is to verify that the system operates as specified in the design, satisfying all functional requirements. This protocol will enable the reviewers to verify that all functional testing of the quality-critical equipment and components including the requirements of 21 CFR Part 11 has been performed and the verification data have been collected and attached to this OQ report. OQ is the final step to formally audit and document proper operation of the system. All functional testing for the system must have been completed in coordination with the engineering department and equipment suppliers prior to this OQ through FAT (Factory Acceptance Test), SAT (Site Acceptance Test), and the subsequent testing activities during Commissioning. Any of the test data can be used as the evidence of OQ, only if such plan and data were approved through the cGMP procedures. When the OQ report is approved, the system is ready for the execution of PQ.