The heart of the change is backstage - a high-tech assembly line that can deliver a prepared-to-order meal in 35 seconds.
That is half the time it used to take McDonald's just to toast a bun.
This will allow more changes - new salads for the health-conscious and special regional dishes, for example.
"We're going to be much more nimble," said Henry E. Gonzalez Jr.
Gonzalez is the Philadelphia native who is the new president of McDonald's Northeast Division, which will move to Philadelphia in August from the corporate headquarters outside Chicago.
In the past, McDonald's restaurants have prepared food in batches, according to the manager's best guess of what will be sold in the next quarter hour.
"I had to look at the people in line and do a lot of analysis to figure out what I thought they would order," said John Converse, general manager of the McDonald's at Front Street and Oregon Avenue in South Philadelphia.
If he guessed wrong, burgers wound up in the garbage.
"A typical McDonald's wastes 100 sandwiches a day. . . . Now we'll throw away only 10 to 15," said Susan McDade, a McDonald's trainer in Philadelphia.
The first sign of the change is at the counter or the drive-through window. As an order is tapped into the cash register, it is flashed on a monitor so the customer can see whether the clerk got it right.
This information is also flashed on a kitchen monitor - in whatever language a worker requires.
A worker puts a bun into a new high-tech device that can toast it in 10 seconds. When the customer pays, the order becomes official, and the buns slide down a heated table. A series of workers apply ketchup with a device that covers the bun with a single squirt, and pile on ingredients, according to what is displayed on the monitors.
While a drive-through order is being assembled, a robotic machine gets an automated message from the cash register, selects an appropriate cup, and fills the drink order.
A computer keeps track of the volume and orders meat - burgers, fish, chicken - that is placed in heated trays over the assembly line. As soon as a tray is loaded, a 20-minute timer starts. Anything left when the timer beeps at zero, Converse said, is discarded.
Another machine loads wire baskets with potato strips, and lines them up to be dropped into the fryer. So they won't have too many fries cooked at any given time, there is a knob that regulates the amount of potatoes in each basket, according to business volume.
The new kitchens are almost quiet, less frantic than before. There's no more shouting, "I need a Quarter Pounder With Cheese!" Now that information passes silently over wires to the kitchen monitors.
"All the young people we hire already know about getting information from a TV monitor," said Charles Ehlers, who owns several McDonald's in Delaware.
A less stressful kitchen, several McDonald's operators said, means less turnover and better teamwork.
The software at each store will become part of McDonald's supply-chain management. Every store computer is already polled late each night by the corporate computer. A huge database is being developed that will help with marketing and, before long, automate delivery of food to McDonald's outlets.
"We want to take the use of that data all the way to the farm, and plan how much lettuce is grown," Gonzalez said.