Sometimes watching Lean Systems can be downright hilarious. At least to me...
A fundamental concept in Lean is the use of Signals. The word "kanban" simply means "signal." And in a Lean System we use signals to trigger action, just in time. Signals are binary and mean one thing, clearly. Andon boards, painted lines, kanban, kaizen plans, standard work charts. All signals.
But I didn't anticipate a signal when my wife and I went to lunch recently. We got into the popular local restaurant ahead of the usual lunch crowd and the place filled up while we ate. We were engaged in a substantive and useful conversation, however, and were oblivious of a) the time and b) the fact that Darrin, our waiter, really really wanted us to move on so he could get another group into our booth and get another tip. Those of you who know me realize I can consume large quantities of iced tea in such a setting and Darrin had been doing a good job of keeping my glass filled.
Then Darrin had an idea for a signal. He stopped by the table, asked if I'd like some more tea and, as he expected, I said yes. Rather than just refill my glass from the pitcher, however, he went back to the kitchen, poured iced tea into a Styrofoam cup that said "To Go" on the outside and plunked it on the table.
A signal. One that said "You are done eating, dude. Take your tea and go. Let me get a tip from someone else." I laughed, admitted defeat and off we went.
Nicely done, Darrin.
Understand your signals.
I hope this is helpful.