Businesses in electricity controls design, supply, install and maintain equipment that regulates or automates the flow and use of electrical power. Their work may cover control panels, switchgear, circuit protection, relays, contactors, timers, sensors and programmable logic controllers (PLCs). Systems are used in factories, commercial premises, public buildings and infrastructure to operate machinery, manage lighting or heating, and monitor electrical equipment. Services can include assessing requirements, producing control schematics, assembling and wiring panels, integrating controls with motors or other machinery, and testing systems before they are put into service. Businesses may also fault-find, repair, upgrade or maintain existing installations, including replacing components and adjusting control software. Some work focuses on industrial automation, while other providers deal with building management or energy monitoring.