SOP means Standard operating Procedure
An SOP is an instruction booklet that describes in detail how to perform a certain action. The goal is of a SOP, therefore, that everyone who has to do the act follows the SOP completely, so that everyone also gets the same result at the end. The SOPs are mainly used in the medical and pharmaceutical industries because it is important that the procedure is carried out in exactly the same way every time (each test subject is treated in the same way). SOPs are also used in the aircraft industry, think of the checklists that pilots follow before they start a flight. Therefore, a SOP is properly checked by several people before it is put into service, so it is certain that the correct procedure is followed. An SOP is not always fixed, and updates can be due to modified materials or machines.
Standard Operation Procedure (SOP) Training [YouTube] rk9n3PHA_oc [/youtube]