Lesson 1. Herbie
We start from the built kit FL-01 «The Dice Game» — the factory, five machines, lamps, two displays, START and a shift of 128 parts. If you don't have it yet, build it from the FL-01 book: this kit is built on top of it. In this lesson we insert nothing — we only make one machine slower than the others and watch how the factory responds.
1.1. Idea: one slow machine
In FL-01 every machine took a second per part. Now machine 3 will take 2 seconds — like Herbie on the hike in «The Goal», who walked slower than everyone. The release stays the same: a part a second.
What should happen? Machines 1 and 2 keep up with everything they get. Herbie — with only half of it. So a queue will start to pile up in front of him, and machines 4 and 5 will get a part once every 2 seconds: they will work every other second.
1.2. Assembly
We add no parts. A machine's time is changed right on it: Alt/⌘ + click on machine 3. At the bottom of the screen you see «Machine: 2 s per item». Each such click is the next time in turn: 0.5 → 1 → 2 → 4 seconds.
1.3. Check
- Switch the power off and on, press R, switch START on.
- Watch for a minute or two.
| What you look at | What you see |
|---|---|
| machine 3's lamp | lit without a break |
| lamps 4 and 5 | blink: lit a second, dark a second |
| buffers of 1–3 | the bar at the bottom is full — a queue |
| source | sometimes cannot release: its exit is taken |
| displays | «made» falls further behind «released» |
By eye it is clear that machine 3 is the problem. But a real plant has hundreds of machines, and «by eye» does not work. In the next lesson we build an instrument that finds the bottleneck by number.
Stuck? Something doesn't work →