What was the name of McDonald's original service concept introduced by the McDonald brothers in 1948?

The McDonald brothers introduced the Speedee Service System in 1948.

After operating a drive-in restaurant, Richard and Maurice McDonald reorganized their San Bernardino, California, business around a limited menu, assembly-line preparation, and rapid counter service. This system was designed to reduce waiting time and make food production more consistent.

The concept was a major part of McDonald's early identity. Its name was represented by Speedee, a chef mascot with a hamburger-shaped head. The system helped distinguish the restaurant from drive-ins that relied heavily on carhops and larger menus.

Ray Kroc later became involved with the McDonald brothers' operation and expanded the franchise nationally. The modern fast-food industry developed through many influences, but Speedee Service System is the specific McDonald's branding and operating term associated with the brothers' 1948 transformation.