On-time is green, yet backlog swings and overtime keeps rising
Question
Our service and shipping SLAs look green, but week-to-week the backlog jumps around, overtime and air-freight keep creeping up, and rework shows up after peak days. Post-promo weeks feel chaotic even when the dashboard says “on plan.” Customers are escalating more. How can everything be “on time” and still feel this unstable?
Answer ✅
Meeting SLAs by pushing harder can hide flow instability. When work bunches, expedites become routine, and staffing flexes late, you hit the date while burning stability. SSM-Audit places a stability band beside the ops KPIs you already track so you can see whether the line is calm and repeatable or spiky and fragile—before it turns into missed commitments and unhappy customers.
What the bands would have shown 📊
• Backlog oscillation index drifting from A+ to A0 / A- (bigger week-to-week swings)
• Expedite share worsening to A- / A– (more rush jobs to meet SLAs)
• Rework/returns rate degrading to A- after peak days
• WIP/throughput ratio tilting A+ → A0 (flow running “hot,” queueing delays rising)
• Staffing volatility slipping to A- (late flexing, weekend spikes)
• On-time without expedite band falling even as headline on-time stays “green”
What to do now 🛠️
- Band the flow: track backlog oscillation, expedite share, rework, WIP/throughput weekly.
- Level the intake: cap late order changes; spread promo fulfillment across more days and waves.
- Set an expedite budget: if expedite share drops below A0, pause new expedites and fix upstream causes.
- Pre-kit high-mix items: reduce rework by staging components ahead of peaks.
- Stabilize staffing: pre-schedule micro-shifts for peak windows instead of last-minute overtime.
- Report “on-time without expedite”: celebrate teams that deliver A+ bands without heroics.
How SSM-Audit helps (practicalities) 🌟
- No additional infrastructure: runs beside your current WMS/OMS/ITSM exports and BI.
- Numbers unchanged: your SLA and cost reports stay the same; stability is a read-only overlay.
- Easy to use: one lightweight weekly panel that operations, supply chain, and CX can share.
- Universal language: A++ / A+ / A0 / A- / A– aligns planners and frontline teams quickly.
CLI 💻 — try our mini Calculator to identify the drift
(Mini CLI Download Page)
Feed your CSV and see bands and drift at a glance (numbers unchanged).
# Backlog oscillation (week-to-week variance)
ssm_audit_mini_calc ops.csv --kpi "Backlog Oscillation Index" \
--out bands_backlog.csv --plot_kpi "Backlog Oscillation Index" --build_id ops
# Expedite share of total orders/tickets
ssm_audit_mini_calc ops.csv --kpi "Expedite Share" \
--out bands_expedite.csv --plot_kpi "Expedite Share" --build_id ops
# Rework/returns rate
ssm_audit_mini_calc ops.csv --kpi "Rework Rate" \
--out bands_rework.csv --plot_kpi "Rework Rate" --build_id ops
# Flow health proxy (WIP / Throughput)
ssm_audit_mini_calc ops.csv --kpi "WIP-to-Throughput Ratio" \
--out bands_wip.csv --plot_kpi "WIP-to-Throughput Ratio" --build_id ops
# On-time without expedite
ssm_audit_mini_calc ops.csv --kpi "On-Time Without Expedite" \
--out bands_ontime_noexp.csv --plot_kpi "On-Time Without Expedite" --build_id ops
Outputs you will get:
- CSVs with stability bands for each timestamp (e.g.,
bands_expedite.csv). - Drift charts per KPI (
--plot_kpi) showing where the flow runs hot. - Optional alerts if you enable thresholds in your setup.
Technical notes
Representation: x = (m, a) with a in (-1, +1)
Collapse parity: phi((m,a)) = m
Order-invariant pooling:
U = sum(w_i * atanh(a_i))
W = sum(w_i)
a_out = tanh( U / max(W, eps_w) )
Typical bands (example):
A++: a >= 0.75
A+: 0.50 - 0.75
A0: 0.25 - 0.50
A-: 0.10 - 0.25
A--: a < 0.10
Navigation
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Page disclaimer
Illustrative scenario for research and education. Observation-only; do not use for critical decisions without independent validation.
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