Book companion resource · Worksheet
Backlog Aging Worksheet
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← Back to toolkit · Browse by chapterTotal backlog is a lie. The real backlog is what you have after the aged, duplicate, and stale items have been removed. This worksheet gets you from the lie to the truth.
Companion to: Fix the System, Chapter 17. Who uses it: the planner, reliability engineer, and maintenance supervisor. When: once in week 1 of the install. Re-run monthly as a health check. Why this exists: plants measure total ready-weeks and stop there. Total ready-weeks tells you how much work has been entered. It does not tell you how much of it is actionable. A plant with 18 weeks of backlog and 40% of it aged beyond 90 days has 18 weeks of noise and 10 weeks of actionable work, and it cannot plan intelligently until it knows which is which.
Step 1 — Export every open work order
From the CMMS, pull every WO currently in the open / planned / waiting status. For each, record:
- WO number
- Asset tag
- Asset criticality (A / B / C from Chapter 15)
- WO type (PM / corrective / project / RCA action / inspection / other)
- Date entered
- Date last touched (status change, note added)
- Estimated labor hours
- Assigned technician (if assigned)
- Parts status (ready / waiting / unknown)
- Current priority
Total open WOs: ________ Total estimated labor hours: ________ Weekly available maintenance labor hours: ________ Total ready-weeks = total hours ÷ weekly hours = ________
Step 2 — Bucket by age
Group every WO by days since "date entered."
| Aging bucket | WO count | Estimated hours | Ready-weeks | % of total |
|---|---|---|---|---|
| Current (0-30 days) | ||||
| 30-60 days | ||||
| 60-90 days | ||||
| 90-180 days | ||||
| 180+ days | ||||
| Total | 100% |
Aged backlog (>90 days) = __________ ready-weeks = ______ % of total
Action threshold: if the aged backlog is >15% of total, you have an aging problem regardless of the absolute ready-weeks number. The aged portion gets the triage first.
Step 3 — Criticality cut on the aged portion
For the 90-180 day and 180+ day buckets combined, break down by criticality:
| Criticality | Aged WO count | Aged hours |
|---|---|---|
| A | ||
| B | ||
| C |
A-class work that has been sitting for 90+ days gets priority in the triage. It is either: (1) being blocked by something that needs escalation, or (2) was never actually A-class and got mis-classified.
Step 4 — Run the four-lever triage (next step is the Decision Tree worksheet)
Every aged WO must be dispositioned via one of four levers before re-entering the active queue:
- KEEP — still valid, still needed, proceeds to scheduling inside 4 weeks
- KILL — no longer needed; log the reason (duplicate / superseded / condition resolved / asset out of service / other)
- DEFER — valid but not a current priority; assign a re-review date (30 / 60 / 90 days out)
- ESCALATE — critical and blocked; route to the plant manager same day
Use the Work Reclassification Decision Tree (ch17-dt-work-reclassification-decision-tree.md) to walk each aged WO through the four levers.
Step 5 — Record the triage result
After the triage, refill the aging table with only the KEEP items:
| Aging bucket | KEPT WO count | Kept hours | Ready-weeks | % of total |
|---|---|---|---|---|
| Current | ||||
| 30-60 | ||||
| 60-90 | ||||
| 90-180 | ||||
| 180+ | ||||
| Total | 100% |
Actionable backlog after triage: __________ ready-weeks
Triage statistics (all aged items, not just kept):
- KEPT: ______ items / ______ hours / ______ % of aged
- KILLED: ______ items / ______ hours / ______ % of aged
- DEFERRED: ______ items / ______ hours / ______ % of aged
- ESCALATED: ______ items / ______ hours / ______ % of aged
Healthy triage: typically 20-40% of the aged portion is KILLED, 20-30% DEFERRED, 10-20% ESCALATED, 20-40% KEPT.
Step 6 — Capacity decision
Compare the post-triage actionable backlog to the target 2-4 ready-week band.
| Post-triage ready-weeks | Diagnosis | Action |
|---|---|---|
| <2 | Discovery gap | Audit the identification process (Chapter 5) |
| 2-4 | Healthy | Install weekly triage meeting, move to Day 60 |
| 4-6 | Mild capacity gap | Rebalance labor first (Day 14-21 lever 1) |
| 6-10 | Capacity gap | Rebalance + contract (levers 1 and 2) |
| >10 | Structural capacity gap | Full Day 14-21 decision: rebalance + contract + hire |
Step 7 — Sign-off
| Role | Name | Signature | Date |
|---|---|---|---|
| Planner | |||
| Reliability engineer | |||
| Maintenance supervisor | |||
| Plant manager (if capacity decision taken) |
What to avoid
- Measuring total ready-weeks only. The aging breakdown is the data that matters.
- Skipping Step 5's triage statistics. The KILL rate is the most diagnostic number in the worksheet. If it is <10%, the triage was not disciplined.
- Running the triage annually. Aged backlog regrows in 90 days. Monthly is the floor. Weekly for the aged portion.
- Treating KILL as admission of failure. It is admission of changed conditions. Log the reasons; the pattern teaches the identification process what to refine.
- Taking the capacity decision before the triage. You cannot decide whether to hire until you know how much of the 18 weeks is real.
End of worksheet. File with the weekly backlog review packet. Re-run monthly.