CFD-03
Thickening Band — Stage Bottleneck
CFD
Default severity: medium
ProcessMetricsOutputRisk
What it detects
Inflow rate to a stage exceeds outflow rate by the configured multiplier for the configured duration.
Detection formula
IF inflow_rate(stage) > outflow_rate(stage) * config.cfd.bottleneck_ratio // default: 1.3 FOR >= config.cfd.bottleneck_min_days // default: 7d THEN FLAG stage as bottleneckExamples in practice
- Cumulative flow bands widen, invert, or stall while throughput fails to keep pace.
- Stage WIP grows without matching completion slope on the CFD.
- A team shows inflow rate to a stage exceeds outflow rate by the configured multiplier for the configured duration while bottleneck ratio is set to 1.3.
Suggested response
Read stage WIP and throughput together; relieve bottlenecks and balance arrival vs capacity.
Coaching playbook
Symptom
Inflow rate to a stage exceeds outflow rate by the configured multiplier for the configured duration.
Why it matters
When "Thickening Band — Stage Bottleneck" keeps appearing, the team is signalling a repeatable process gap. Left unexamined, the pattern hides where work really stalls and makes improvement metrics harder to trust.
What you can achieve
Read stage WIP and throughput together; relieve bottlenecks and balance arrival vs capacity.
Facilitation questions
- What system change would stop "Thickening Band — Stage Bottleneck" from firing again?
- What do the cited issues have in common — same root cause or same workaround?
- Who owns the two-week experiment and how will we verify on the next import?
Run this rule against your own tracker data with Flow Analyzer.