Performance Qualification of old Rapid Mixer Granulator

Dear Sir,

I wanted to do PQ for the old equipment (RMG) in our company.
this is old equipment and is in use from last few years also Process Validation of few products already done on the same. But this equipment dont have PQ in place.

I have tried with retrospective approach too but because of lack of data it is not possible to comply. SO decided to do PQ of the equipment.

Can you advice me to design PQ protocol for rapid mixer granulator (considering situation mentioned above) including how to decide batches? Do I need to consider actual product or placebo in this case?

Thanks in advance.