This standard specifies the technical and managerial requirements for operational maintenance, repair, and tests of distributed control systems (DCSs) in power stations. This standard is applicable to the operational maintenance, repair, and tests of DCSs in conventional thermal power stations after commencement of commercial operation. IEEE Std 1865(TM) specifies the general requirements applicable to all standards in the IEEE 1865 series. IEEE Std 1865.1(TM) and IEEE Std 1865.2(TM) concentrate on more specific topics. IEEE Std 1865.1 provides detailed requirements for the repair and test of DCSs, including items, methods, and procedures. IEEE Std 1865.2 provides detailed requirements for the operational maintenance and management of DCSs, including items, methods, and procedures.