There are many problems. Only one sets the pace. Nora found the pace-setter hiding in plain sight, humming at 400°F. Nora runs a bagel shop. Mornings are chaos. Line out the door. Staff sprinting. Cash? Meh. She blames marketing. Then prices. Then “people these days.” Nothing changes. A friend hands her an old book “The Goal” by Eliyahu M. Goldratt. “Your shop is a pipe,” he says. “Money flows at the speed of the narrowest part. Find the narrow part. That’s Herbie.” Nora walks the line with a coffee and a stopwatch. • Dough station: fast. • Toppings: fast. • Toaster: not fast. A graveyard of bagels waits there. Orders pile up. Customers wait. Staff look busy. The drawer isn’t. Step 1 — Identify (find Herbie). The toaster is the bottleneck. Everything else is noise. Step 2 — Exploit (feed Herbie). She puts her best person on the toaster. No side tasks. No phone. No “can you grab napkins?” Pre-slice popular bagels in batches. Pre-portion cream cheese. 80/20 menu: push top sellers that toast evenly. Toaster stays busy on high-value orders only. Step 3 — Subordinate (make everyone march to Herbie). Cashier paces orders to match toaster cadence—no more flooding the queue. Prep team builds a small “buffer” tray of ready-to-toast bagels so the toaster never starves. Hosts hold new orders when the buffer dips. The toaster sets the beat. It’s the drum. This is Drum–Buffer–Rope in street clothes: • Drum: the toaster’s pace. • Buffer: a few ready items before the toaster. • Rope: a pull signal so upstream doesn’t overload it. Step 4 — Elevate (upgrade Herbie, last). Only after two weeks of clean flow does Nora buy a second toaster and trim two slow menu items. Now the line moves. Waste drops. Cash jumps. Step 5 — Repeat (new Herbie). With toasting fixed, the new choke is card checkout at 8:45 a.m. She adds tap-to-pay and a second reader. Flow improves again. Three numbers tell the story: • Throughput (T): dollars out per hour. Up. • Inventory (I): half-made orders waiting. Down. • Operating Expense (O): same staff, less chaos. Flat to down. No brand refresh. No billboard. No pep talks. Nora just widened the narrowest part first Many companies die of indigestion, not starvation. Don’t pour more into a clogged system—clear the clog and the numbers get louder on their own. Write this on a sticky note for one week: “What’s the slow step today?” Answer it each morning, fix one friction, fix it, and watch the cash register keep better time.