CF Dictionary · Theory of Constraints Terms
Excess Capacity
When a factor has more capacity than the system needs. ToC says don't optimise it — it's not the constraint.
Excess capacity is when a factor has more capacity than the system needs. A machine that can produce 1000 units/hour when only 100 are required is excess.
Why ToC says "don't optimise it"
- It doesn't help throughput. The bottleneck is still the bottleneck.
- It can hurt. Speeding up excess-capacity steps produces inventory piles.
- It's a local-optimum trap. Looks like improvement, isn't.
When excess capacity is good
- As buffer. Some excess protects against variance.
- As redundancy. For critical steps.
- As design margin. Margins of error are deliberate excess.
CF's framing
CF treats excess capacity as one of three classes of factor:
| Class | Status | Action |
|---|---|---|
| Constraint | Near breakpoint | Focus here |
| Excess capacity | Way above breakpoint | Don't optimise |
| Impossible | Way below breakpoint | Skip |
Where excess capacity lives
- Most of your systems. Most steps in most processes have excess.
- Easy projects. Where you don't even notice the difficulty.
- Routine skills. Once automatized.
"Most factors have excess capacity and should not be optimized." — criticalfallibilism.com