Results of NYK Group Joint Research on CBM Adopted in Second Edition of ClassNK Guidelines The results of joint research conducted by NYK Line and MTI Co., Ltd. (MTI) since November 2019 on realizing condition-based maintenance (CBM)* for main diesel engines has been adopted by ClassNK in “CBM Guidelines (Edition 2.0)”. Background In the shipping industry, time-based maintenance (TBM)** is usually practiced, but TBM requires a vessel to halt operations for a few weeks of inspections every two or three years even if no fatigue or breakdown of the engine is observed. Moreover, unexpected failures can occur during voyages and cause long delays. With recent developments in information and communication technology, large amounts of data can now be transmitted between ship and shore, so since November 2019, NYK and MTI, together with ClassNK and engine manufacturers, have been conducting joint research on using CBM to optimize maintenance.