Best Practices for Crude BS&W accounting for Petroleum Refinery

[PetroDDP]

One of the major component for Petroleum Refinery "Unaccounted loss" is Receipt Crude BS&W at Tank farm from Jetty through Ship.Is there any best practices/methodology for Crude BS&W accounting in Refinery overall yield accounting methodology. There are various steps for Crude BS&W measurement at Refinery end , like by surveyor, at Ship Composite tank (STC) , at Tank farm end , at Laboratory end etc. However, to have more accurate Crude Receipt BS&W measurement International best practices would help.

Thanks & Regards,