CA-02
System-Level WIP Accumulation
CFD Advanced
Default severity: medium
PrioritizationProcessMetricsOutputRisk
What it detects
Arrival rate persistently exceeds throughput rate — total system WIP is growing. Time-to-crisis is projected based on current rates. arrival_rate = AVG(new_issues_per_period, config.ca.rate_averaging_window) // default: last 3 periods throughput_rate = AVG(done_per_period, config.ca.rate_averaging_window)
Detection formula
IF arrival_rate > throughput_rate THEN FLAG periods_to_crisis = current_wip / (arrival_rate - throughput_rate) IF periods_to_crisis \< config.ca.crisis_horizon // default: 3 periods THEN CRITICALExamples in practice
- A team shows arrival rate persistently exceeds throughput rate while crisis horizon is set to 3 periods.
- Example signal: Arrival rate persistently exceeds throughput rate — total system WIP is growing.
Suggested response
Use planning-event context when interpreting advanced CFD bottlenecks, spikes, and ageing WIP.
Coaching playbook
Symptom
Arrival rate persistently exceeds throughput rate — total system WIP is growing. Time-to-crisis is projected based on current rates. arrival_rate = AVG(new_issues_per_period, config.ca.rate_averaging_window) // default: last 3 periods throughput_rate = AVG(done_per_period, config.ca.rate_averaging_window)
Why it matters
When "System-Level WIP Accumulation" 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
Use planning-event context when interpreting advanced CFD bottlenecks, spikes, and ageing WIP.
Facilitation questions
- What system change would stop "System-Level WIP Accumulation" 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.