A building management system bms is a computer, Based control system installed in buildings that controls and monitors the building s mechanical and lighting fire systems, Electrical devices, Power systems and security, Including ventilation systems. A bms is most common in an expansive building. Its core function is to handle the environment within the building and may control temperature, Carbon dioxide levels and humidity within a building. As a core function in most bms systems, It controls heating and cooling, Manages the systems that distribute this air throughout the building for instance via operating fans or opening/closing dampers, And then locally controls the blend of heating and cooling in order to reach the desired room temperature. A secondary function sometimes is to observe the extent of human, Generated co2, Mixing in outside air with waste air to boost the quantity of oxygen while also minimising heat/cooling losses. Systems linked to a bms typically represent 40% of a building s energy usage, If lighting is included, This number approaches 70%. Bms systems are a critical component to managing energy demand. Improperly configured bms systems are believed to account for 20% of building energy usage, Or approximately 8% of total energy usage within the country states.