How to Find the Bottleneck in a Business Process
Every slow process has one step where work piles up. Fix that step and the whole process speeds up; fix any other step and nothing changes. Here is how to find it — on paper and with a simulator — and how to choose the fix.
Process improvement · 2026-10-23 · 8 min read
What a bottleneck really is
A bottleneck is the step whose capacity is closest to (or below) the demand placed on it. When work arrives faster than a team can finish it, a queue forms — and the queue, not the work itself, is usually most of the time a case spends in the process.
Tip: In most processes, cases spend far more time waiting than being worked on. That is why speeding up the work at a step that has no queue rarely helps.
Utilisation: the number that predicts queues
Utilisation = work arriving ÷ capacity. If 20 cases a day each need 30 minutes of a reviewer's time, that is 600 minutes of work; one reviewer working 8 hours has 480 minutes — 125% utilisation, so the queue grows every day. Two reviewers have 960 minutes — 63%, so the queue stays small.
| Utilisation | What happens |
|---|---|
| Below 60% | Little waiting; spare capacity |
| 70–85% | Noticeable queues at busy times |
| 85–100% | Long waits; small changes in demand cause big delays |
| Above 100% | The queue grows forever — cases never catch up |
Find it in four steps
- Draw the process as a swimlane or BPMN diagram, one lane per team.
- Add numbers: how long each step usually takes, how many people each team has, how often each decision goes each way, and how many cases arrive per day.
- Run a simulation of a few weeks of work and look at waiting time per step and utilisation per team.
- Test fixes — one more person, a faster step, removing a step — and compare time per case and cost before you change anything.
Example: A support process ready to simulate: L1 support, L2 engineers and the customer.
Common fixes, and when they work
| Fix | Works when | Watch out for |
|---|---|---|
| Add a person to the bottleneck team | Utilisation is above ~85% | Cost per month; the bottleneck may move |
| Make the bottleneck step faster | The step is slow, not just busy | Training, templates and automation take time to land |
| Remove or merge a step | The step adds little value | Approvals that exist for a reason (compliance, risk) |
| Route fewer cases to the bottleneck | An earlier step can solve more cases | Quality of the earlier step |
In AI Flowchart, 🎯 Find the best fix tries every one of these automatically and ranks them by time saved and monthly cost.
Try the insurance-claim simulation →
Frequently asked questions
What is a bottleneck in a process?
The step with the least spare capacity compared with the work arriving at it. Work queues in front of it, and it limits how many cases the whole process can finish.
How do I calculate utilisation?
Work arriving per day (cases × minutes per case) divided by capacity (people × working minutes per day). Above about 85%, waiting times rise sharply.
Is the process simulator free?
Yes — drawing, simulating and seeing the bottleneck are free. What-if comparisons, Find the best fix and report downloads are part of Pro.