McDonald's introduced its Speedee Service System in 1948.
Maurice and Richard McDonald redesigned their San Bernardino, California, restaurant around a limited menu, assembly-line preparation, and rapid counter service. They reopened the operation in December 1948 with the new system, which helped establish the model later associated with modern fast food.
Speedee was also used as an early McDonald's mascot. The character was a chef-like figure with a hamburger-shaped head and appeared in the company's early visual identity before Ronald McDonald became the dominant advertising character. The name therefore refers both to a service concept and to an early brand symbol.
A common mix-up is dating the system to Ray Kroc's arrival in 1954 or to the opening of the first franchised McDonald's in 1955. The system itself began earlier, when the McDonald brothers rebuilt their original restaurant around speed and standardization.