SOP For In-Process Checks For Double Cone Mixer is described in this post which you can follow in the section of the Quality Assurance Department.

This procedure has been established to outline for in process inspection to be conducted before and after mixing process to ensure the quality of product.
This procedure is applicable to all mixing areas of the Production Department 
QA Officer
Manager Quality Assurance 
QA Officer checks the cleaning status of the mixer and ensures that it is free from dust, powder or foreign matter.
QA Officer Confirms the swab test report of mixer in BMR before line clearance. If it’s not done, then perform swab test.
QA Officer checks the Identification label which includes Name of Product, Batch No, Batch Size, Process/Status, Signature (Production Officer) and Date.
QA Officer Checks machine cleaning log card for compliance.    
QA Officer ensures the personnel working in the area wear proper mask, gloves, and shoes.
QA Officer checks that the mixer is working properly and also checks that it should not produce any abnormal sounds and require maintenance.
QA Officer checks whether the Air Conditioning and exhaust systems are working properly.
After checking all the above mentioned parameters of mixer, QA Officer gives line clearance for manufacturing.