This document specifies requirements and procedures for the performance test to verify the mechanical features of the liquified natural gas (LNG) boil-off gas (BOG) re-liquefaction system on board a ship. These test procedures can be prepared for LNG BOG re-liquefaction systems of LNG ships such as LNG carriers, LNG bunkering vessels and LNG fuelled vessels. Functions which are specific to manufacturers and any additional tests or specifications required by clients are not covered in this document.