Foundation Fieldbus (FF) Technology has become common in process control systems in all over the world. However, this technology is not common in Japan. JGC has gained wide engineering experience using this technology for overseas plant construction projects. This technology applies to both field measurement devices and the distributed control system (DCS) and has changed the field data transmission from analog to digital communication. New additional engineering steps are required for FF technology in the current engineering sequence. The major new consideration in engineering work is segment validation and cycle time validation, to confirm the communication link. FF technology also leads the new field device maintenance technology.