In 30 seconds
- Throughput is limited by one constraint.
- Five focusing steps: identify, exploit, subordinate, elevate, repeat.
- Improving non-bottlenecks wastes effort.
Origins
Eliyahu Goldratt introduced the theory of constraints in his 1984 business novel The Goal.
Five focusing steps
- Identify the constraint.
- Exploit it: make sure it never waits.
- Subordinate everything else to it.
- Elevate it: add capacity if still needed.
- Repeat: find the next constraint.
In software delivery
Common constraints include code review, testing, a shared environment or one expert. A widening band on a cumulative flow diagram or a long queue points to it. WIP limits help subordinate other steps to the bottleneck.
Myth vs reality
Myth · Make everyone busy to go faster.
Reality · Non-bottlenecks working harder just builds queues.
Myth · The constraint never moves.
Reality · Fixing one reveals the next.
Myth · TOC is only for factories.
Reality · It applies to any flow of work.
FAQ
How do we find the constraint?
Look for where work piles up waiting.
What does subordinate mean?
Pace other steps to the bottleneck's capacity.
Is TOC related to Kanban?
Yes; Kanban's flow focus applies many TOC ideas.