Every vehicle sitting in your shop is cash you haven't collected yet.
Parts purchased but not billed. Labor invested but not invoiced. Bay space occupied but not generating revenue.
That's Work in Process—and when it ages, it kills your cash flow.
What Is WIP Aging?
WIP aging tracks how long vehicles have been in your shop:
- 0-7 days: Healthy. Repairs are moving.
- 8-14 days: Watch list. Some may be complex repairs; some may be stalling.
- 15-30 days: Concern. These need attention.
- 30+ days: Problem. Something is wrong.
A shop with 40 cars in WIP could be healthy or in trouble. The age distribution tells you which.
Healthy WIP distribution:
- 25 cars (62%): 0-7 days
- 10 cars (25%): 8-14 days
- 4 cars (10%): 15-30 days
- 1 car (3%): 30+ days
Unhealthy WIP distribution:
- 15 cars (38%): 0-7 days
- 10 cars (25%): 8-14 days
- 10 cars (25%): 15-30 days
- 5 cars (12%): 30+ days
Same total. Very different story.
Why Aging Matters
Cash Flow Impact
A vehicle that sits for 30 days is 30 days of parts you've paid for but not billed, labor you've paid for but not collected, and bay space not available for new work.
At $5k average repair value, 10 vehicles aging past 30 days is $50k in trapped cash.
Cycle Time Drag
Every aging vehicle eventually gets delivered—and wrecks your cycle time metrics when it does.
Customer Experience
Customers waiting 30+ days aren't happy customers. They're calling daily, leaving bad reviews, and complaining to insurance carriers.
The Aging Causes
1. Parts Delays
The most common cause. A vehicle waiting 3 weeks for a backordered part ages your WIP whether you like it or not.
2. Supplement Loops
Repairs that go through multiple supplement rounds with adjusters. Each round adds days or weeks.
3. Customer Delays
Customers who don't respond to calls, don't pick up their vehicles, or can't make decisions.
4. Internal Bottlenecks
Capacity constraints that create queues at specific stages—paint, assembly, detail.
5. Forgotten Vehicles
The worst kind—repairs that simply fall through the cracks. Everyone assumes someone else is handling it.
Building the WIP Aging Dashboard
Shop-Level View
| Shop | Total WIP | 0-7 days | 8-14 days | 15-30 days | 30+ days |
|---|---|---|---|---|---|
| Downtown | 35 | 22 (63%) | 8 (23%) | 4 (11%) | 1 (3%) |
| Eastside | 42 | 20 (48%) | 12 (29%) | 7 (17%) | 3 (7%) |
| Northgate | 28 | 18 (64%) | 6 (21%) | 3 (11%) | 1 (4%) |
Alerting on WIP Aging
Don't wait for someone to check the dashboard. Set up alerts:
- Any vehicle crosses 25 days → Notify shop manager
- Any vehicle crosses 35 days → Notify regional manager
- Shop's 30+ count exceeds 5 → Notify leadership
Delivered Not Closed: The Revenue Leak
Related to WIP aging is Delivered Not Closed (DNC)—vehicles delivered to customers but not invoiced in CCC.
This is pure revenue leakage: car is gone, customer is happy, but the invoice hasn't been sent and payment isn't coming.
Track it daily. Any vehicle delivered more than 3 days ago and still open is a problem.
WIP Aging as a Leading Indicator
Here's the key insight: WIP aging predicts future cycle time.
Today's 20-day vehicle is next month's cycle time problem. By tracking aging, you can see trouble coming before it hits your delivery metrics.
- Rising 15-30 day count → Cycle time will increase in 2-3 weeks
- Rising 30+ count → Cycle time will spike in 4-6 weeks
- Flat or declining aging → Cycle time will stay stable or improve