Since the 1990s when HollySys entered the power industry (200MW unit at Changshan Power Plant), HollySys' DCS systems have been widely used in the power plant control engineering industry. During the many years of engineering practice, HollySys collaborated with major power groups, power design institutes, and power debugging units. It combined the characteristics of HOLLiAS-MACS based on the process characteristics of different types of  generators, and designed different types of solutions such as coordinated control systems (CCS), modulation control systems (MCS), bypass control systems (BPCS), sequence control systems (SCS), Furnace Safety Supervisory System (FSSS), Electrical Control System(ECS), Digital Electric Hydraulic Control System (DEHCS), Flue gas desulfurisation (FGD), air cooled condenser (ACC), and balance of plant (BOP) with the objective of providing a holistic solution to its clients. The HOLLiAS-MACS DCS system has been successfully applied in more than 100 300MW++ major thermal power units, including applications on 600MW and 1000MW units.