Validation & Change control

Is incorporation of new equipments requires change control intially or it can be raised after validation is completed?
Eg., A product undergoes blending in double cone blender (DCB)& validated for the same.But due to improper mixing blending process has been shifted to octagonal blender(OGB).In this case
A) Equipment qualification (PQ) should be done for the blender.So the first 2 or 3 batches going in this OGB will be considered as validation or optimization batch?
B) In case if it is considered as validation batch on what basis (supporting documents) the concerned product batch record ,validation protocol & MFR will be changed? Is this is possible???
C) In case of the above point(b),without knowing the correct blending time how can a change control be raised for change of documents?Is it required to take 2 change controls (tentative & permanent change control for mixing time) – (1) to incorporate the new equipment in batch record (Intially) (2) To change the mixing time after sucessful completion of 3 validation batches?
D) or else deviation should be raised first for deviating the validated manufacturing process & based on that change control will be raised & process will be validated?
Can anyone help out to clarify these points?

Before going to the options in this project let me clear myself on line mentioned by you “A product undergoes blending in double cone blender (DCB)& validated for the same” is indicating that validation is completed successfully.
If problem arises after completion of validation, then it’s a failure of process adopted & deviation to be raised.
Its not that easy that when blending fails in DCB, it should be done in OGB. A detailed study for the occurred deviation/ non-confirmity to be done & in coordination with the R&D. Then only the process or equipment selected can be changed.
Option I would do is:
Observe the Blending time & results of another/Prev Blended batch for same product and then come to a Opinion before changing the process/equipment