There are probably several business journal papers and articles written on this topic already but here is my own take on how the Chinese dim sum restaurants are doing (almost) everything right. I've been going to dim sum in Arcadia ever since I moved to Pasadena in '95 (Chinatown and Monterey Park before that) and the efficiency of how they run the business is amazing. First of, I cannot think of any big restaurant where within 60 seconds of sitting down, I have food at the table. Typically, half dozen carts with food roam the aisles between tables so for a restaurant with about 3 aisles, I'm looking at 2-3 carts per aisle at all times. Odds are always good I'll be eating before the tea and hot sauce even arrive. As soon as I'm seated, I am given a tab at my table that is stamped for every item I choose from the carts.
Also at dim sum, your table is not assigned a waiter. Meaning every employee helps the customer with any need -- none of this "not my job" excuse. Need a dish you haven't seen stroll by, just ask and within minutes, they personally bring you the plate straight out of the kitchen steamer. Speaking of plates, there is a tendency to accumulate empty plates on the table but they also have a solution for that. Several waiters/bus boys roam the aisles back and forth picking up empty plates, thereby making more room for new dishes. I estimate a plate gets picked up within a 2-3 minutes of it being emptied. The less there is to clean up to set up for the new customer, the better for the business. I've seen a table for four cleared, tablecloth changed, plates/teacups/chopsticks/napkins arranged in about 30 seconds.
And for a restaurant with no menu, the food just keeps on coming. The absence of a menu makes it easy for the chefs to prepare the same dishes but most importantly, there are no orders to screw up. And when I've had too much to each (happens every time), I just wave the tab and within seconds, any one of several waiters will arrive, count the stamps, add the bill and hand me back the total. Yes, these waiters can add -- and add quick, given that most of the dishes cost the same amount.
There are still a couple problems with dim sum though. First, the wait can be long and I've learned to avoid that by showing up before 10am on weekends. Also, the bathrooms aren't the cleanest (meaning the kitchen is probably kept at the same standard of cleanliness but I don't want to know for sure). Both of these seem to be a direct result of the volume of business that they do. Nevertheless, American businesses can learn from this business model that had served over a billion people quite well for a very long time.