🍾Bottleneck

The step with the least capacity in a chain. It sets the output of the whole chain, whatever the other steps can do.

Goldratt's version, from 📕 The Goal, in my words: an hour lost at the bottleneck is an hour lost for the entire plant, and an hour saved anywhere else is a mirage. In the novel it is the slowest boy on a scout hike. The line can only move at his pace, so you put him at the front and carry his rucksack.

• Work piles up in front of it. To find the bottleneck, look for the pile.
• Steps upstream that run flat out only make the pile bigger.
• Steps downstream are starved and look idle. They are not the problem.

Often confused with: the busiest team, or the team people complain about. Busy is not evidence.

The method that follows from it is 🧭 Five focusing steps. My notes on the book are 📖 Goldratt on bottlenecks.

Where I have seen it

QA, in the launch. In January and February I kept feeding design and engineering, because that was where I had influence, while everything queued in front of testing. Nadia Rahimi had told me the load test was too gentle. The pile was in front of her team the whole time.

That became 💎 A bottleneck sets the pace for everything upstream of it, written on 9 February, three days before I had to recommend the slip.

Since November I have been asking the same question of support queues, with less confidence: 🔭 Queueing theory for support and dispatch. There the constraint may be variation and not headcount.