The “Speedee Service System” is the founding innovation: the McDonald brothers applied the logic of the assembly line to a restaurant. A menu reduced to a few items, no customised orders, no waiters, no crockery, specialised workstations. The customer waits a few dozen seconds for his hamburger instead of twenty minutes, and the price falls.
It was they, and not Ray Kroc, who devised the method. Kroc saw it working, understood its value, and built a national network around it — something the brothers, cautious and not much interested in expansion, had not wanted to do.
In 1961, they sold for 2.7 million dollars. One detail shapes the entire later legend: the sale covered the name, and their own restaurant was excluded from it — so they could no longer call it McDonald's. It became “The Big M”, and closed a few years later. The account according to which Kroc deliberately opened a restaurant across the road to kill it, like the oral promise of a 0.5% royalty, comes from the film The Founder and from Kroc's autobiography, not from documents.