It should be noted that the Site Acceptance Testing and the Operation Qualification Testing largely fulfil the same objectives (testing against the Functional Specification) and that these may usefully be performed at the same time or combined.
Note that decisions on the need for Factory and Site Acceptance Testing, the timing of these with the respect to the IQ and OQ and the possible combination of these may be taken in the early stages of the project. This decision should be documented as part of the Validation Master Plan or in the Project Quality Plan. If this is not the case, the relationship between Factory Acceptance Testing and Site Acceptance Testing should be documented in the Test Strategy.
http://www.askaboutvalidation.com/the-relationship-between-iq-oq-fats-and-sats/