Visit a fast food restaurant and observe to get a cheap lesson in Lean. Two restaurants that are my favorites in displaying a cheap lesson in lean are In-and-Out Burger and Subway.
Both restaurants exceed in providing fresh food. Some of the key Lean concepts I observed were:
Singe piece flow: In subway and In-and-Out Burger they run a sandwich based assembly line in a single piece flow. Depending on load one worker will either produce your whole order or they will have an assembly line of workers that rapidly produce what you ordered one piece at a time.
Pulled by customer demand: At Subway they only make what you want and when you want it. This helps to minimise wastage and overproduction and allows them to always have fresh sandwiches. At In-and-Out Burger I found that they will produce the whole order after you order. They produce in single batches.
Clear visualisation and simple choices: Subway has an unlimited number of options, but with clearly visible and easily recognisable choices. As you are ordering everything is visible and even if you do not know the language you can still order exactly what you want through good visualisation.
Producing in small batches: You can clearly see that the end sandwiches are produces in small batches, one at a time. However I also observed that at In-and-Out Burger they were making the potato chips from raw potatoes in small batches. They have a small simple machine that they use to make small batches of potatoes when they are needed. At Subway you can see the replenishment of their containers from the fridge. Once they have used one container of tomatoes, they will send the empty tomato container away and then replenish it with a new one. I am not sure what the empty container kicks off, but it could be used as a Kanban to signal to purchase of another container of tomatoes.
So if you want a cheap lesson in lean go to one of your favourite fast food stores and observe how they meet your demand.