Honeywell traces its roots to 1885 with Albert Butz's firm, Butz Thermo-Electric Regulator, which produced a predecessor to the modern thermostat. Other inventions by Honeywell include biodegradable detergent and autopilot. Today, Honeywell is a global multi-industry behemoth with one of the largest installed bases of equipment. It operates through four business segments: aerospace technologies, industrial automation, energy and sustainability solutions, and building automation. Recently, Honeywell has made several portfolio changes to focus on fewer end markets and align with a set of secular growth trends. The firm is working diligently to expand its installed base, deriving around one third of its revenue from recurring aftermarket services.