Takt time is calculated as the amount of manufacturing time that is available divided by the volume of orders. In the 1930s, the German aviation industry employed Takt for the first time as a production management tool. The idea was widely used within Toyota in the 1950s, and by the late 1960s, it had been adopted by the majority of the Toyota supplier base. Every month, Toyota assesses the takt for a process, with a modifying review occurring every 10 days. Takt time is used to properly balance supply and demand. It gives a lean production system its beating heart.