In a prior life, I used to be a McD's restaurant manager. It always amazed me then how frequently they changed things to make things more efficient.Actually -- as a current McDonald's Canada employee, I can tell you this:
Fresh, whole, Grade A eggs are used in the McMuffin sandwich line, liquid eggs from a carton are used for the scrambled eggs (part of the Big Breakfast... something I believe the American menu does not include?) and the folded egg that comes on the Bacon and Egg Bagel and McGriddle sandwiches is thawed from frozen and heated up on the clamshell grill before placement in the sandwich.
When I started, there were only fresh eggs ... no cartons of PWE (pasteurized whipped eggs). For the folded eggs and scrambled eggs, you had to crack open fresh eggs into a cup and whisk the heck out of them before you cooked them (otherwise they'd come out too thin).
I'm quite happy to have an IT career nowadays, but there's some stuff I still miss about working at McDs.