Kanban column with a growing queue IS the bottleneck — no…
When cards accumulate in one column of a kanban board creating a visible queue, treat that column as the current bottleneck without requiring separate cycle time analysis.
When This Fires
- Glancing at a kanban board and noticing one column with significantly more cards than others
- During team retrospectives when discussing flow and throughput
- When deciding where to focus process improvement efforts
- Any time you're trying to identify what's limiting team throughput
Common Failure Mode
Ignoring the visual signal because the column has "always looked like that." A chronically full column is a chronic bottleneck — the fact that it's familiar doesn't mean it's not constraining. The other failure mode: demanding quantitative analysis before acting. If 12 cards are sitting in "Code Review," you don't need a spreadsheet to confirm that code review is the bottleneck. You need to address the queue.
The Protocol
When you see cards accumulating in a kanban column: (1) Name the bottleneck: "[Column name] is our current constraint." (2) Ask: why is the arrival rate exceeding the processing rate? (Too few reviewers? Too large PRs? Reviews taking too long?) (3) Intervene: stop starting new work and redirect capacity to clear the queue. In kanban terms: "stop starting, start finishing." (4) Monitor: does the queue shrink? If yes, the intervention worked. If not, investigate deeper causes.