Bottleneck Calculator
The throughput of a process made of several steps — the slowest step sets it — with the bottleneck identified, the idle share of every other step and the output over a shift.
A line moves only as fast as its slowest station: whatever the others can do, work piles up in front of the constraint and the rest starve or wait.
How the bottleneck calculator works
A line moves only as fast as its slowest station: whatever the others can do, work piles up in front of the constraint and the rest starve or wait. Enter each station’s capacity in units per hour; the minimum is the system throughput, and each other station’s utilisation is the throughput divided by its own capacity. Speeding up anything but the bottleneck changes nothing — the core of the theory of constraints.
Formula: throughput = min(rate₁ … rateₙ); utilisationᵢ = throughput ÷ rateᵢ
Worked examples
| Inputs | System throughput | Note |
|---|---|---|
| 120 / 95 / 150 / 110 units per hour | 95 units/h | 95 — station 2; 712 a shift |
| A balanced line | 100 units/h | 100 |
| One slow inspection step | 60 units/h | 60 — the inspection |
FAQFrequently asked questions
Why does improving other stations not help?
Their extra capacity has nothing to work on: the bottleneck feeds them at its own pace, or they feed it faster than it can take. Time and money spent off the constraint raise inventory, not output.
What if the bottleneck moves?
It always does — once you speed up the constraint, the next-slowest station becomes it. The last row shows where; the theory of constraints is a cycle of identify, exploit, subordinate, elevate, repeat.
What about variability?
Real stations fluctuate, and variability before the bottleneck starves it. A buffer of work in front of the constraint keeps it fed; the calculation here is the steady-state ceiling.
Does this apply to offices and software?
Yes — approvals, code review, a single specialist, a shared test environment. Wherever work queues, the queue is at the constraint.
Where these figures come from
- Corporate Finance Institute — EBITDA — why EBITDA is a non-GAAP measure with no single definition
- US SEC — Non-GAAP Financial Measures, Compliance & Disclosure Interpretations — the disclosure rules that exist precisely because EBITDA is not standardised
- Australian Securities and Investments Commission — the Australian corporate regulator
Last checked: September 2026. These are standard management-accounting definitions; where a term has no single agreed definition, the page says so.