Setting WIP limits
Start with what the team is currently doing on average and set the limit slightly below it. Watch for bottlenecks. Adjust. The classic mistake is starting with the team's aspirational target — it gets gamed within a sprint.
Classes of service
- Standard — most work. FIFO within the column.
- Expedite — urgent. Skips ahead. Limited to 1 active expedite at a time (otherwise everything is urgent).
- Fixed-date — has an external deadline. Sequenced by due date, not arrival.
- Intangible — long-term work (refactoring, tech debt) that's easy to deprioritize. Reserved capacity protects it.
Cumulative Flow Diagram (CFD)
CFD is a stacked area chart over time, one band per workflow state. The width of any band at a point in time = WIP in that state. The vertical distance between "In Progress arrival" line and "Done" line at a given point = average cycle time.
↳ what a healthy CFD looks like
Smooth, parallel bands moving up over time. Sharp angles in one band = sudden WIP spike (a bottleneck). A band that grows continuously = cards getting stuck there. Use it weekly to catch flow problems before they become schedule problems.