7 Parts Department Numbers You Should Be Tracking Every Month
Where to find them, what they tell you, and how to use them to grow sales and gross profit.
You probably know your monthly parts sales. You likely know your gross profit percentage, too.
But those numbers don't tell the whole story.
They show what you've sold. They don't always show what you could have sold.
Here are seven things worth checking to find out where you're making money, where you're losing it, and what to do next.
1. Gross Profit Dollars
Are You Making More Money or Just Protecting Your Margin?
Gross margin matters, but it doesn't tell you how much money your department is actually generating.
Consider two scenarios:
Scenario A
$17,500
Gross profit
Scenario B
$20,000
Gross profit
Scenario B generates $2,500 more gross profit.
Where to find it: Check your DMS parts sales or gross profit report. If gross profit isn't listed, subtract cost of goods sold from sales.
What to do with it: Compare gross profit dollars month over month, alongside sales and gross margin. If sales are increasing but gross profit isn't keeping pace, review pricing, discounts, and sales mix.
2. Lost Sales
How Much Business Are You Turning Away?
A customer asks for a part. You don't have it. They leave without buying.
If that request isn't recorded, it disappears from your reporting.
Lost sales help you understand how often customers are asking for parts your department can't supply at the time they need them.
Repeated requests are worth investigating before changing stocking levels.
They can also reveal patterns. Maybe you're repeatedly missing the same fast-moving part. Maybe certain repair categories generate more requests than your inventory supports.
Where to find it: Start with your DMS lost-sales report. If your team doesn't consistently record lost requests, use a simple log with the part number, quantity, date, and reason.
What to do with it: Identify recurring requests, then compare them with stocking levels and lead times. Focus on opportunities where demand justifies the inventory investment.
3. Parts Fill Rate
How Often Do You Have the Part When It's Needed?
Fill rate measures how often you can meet parts requests from available stock.
If customers request 100 parts and you can fill 90 from stock, your fill rate is 90%.
90 filled10 not filled from stock
That remaining 10% deserves attention.
Some of those parts may be unusual requests that aren't worth stocking. Others may be parts you should have on the shelf but keep running out of.
Where to find it: Look for fill rate or stock availability reports in your DMS. Confirm whether your system measures requests, line items, or quantities.
What to do with it: Review repeat stockouts against reorder points, stocking quantities, and supplier lead times.
4. Sales by Customer Type
Where Is Your Revenue Coming From?
Your total sales tells you how much you sold, not who's buying.
Breaking sales down by customer type shows which parts of your business are growing and which are slowing down.
Your department might be growing overall while retail counter sales decline. Or online orders might be bringing in customers nationwide who would never have called or visited your dealership.
That distinction matters. Different customer types represent different sources of demand, and each can add to gross profit.
Where to find it: Use DMS sales reports by account or transaction type. If you sell through a webstore or marketplace, review those reports too, avoiding double-counting.
What to do with it: Compare sales and gross profit by customer type. Look for declining categories and opportunities to reach customers beyond your existing accounts.
5. Inventory Turnover
Is Your Inventory Working for You?
Inventory ties up money. Turnover helps you understand how quickly that inventory sells and gets replaced.
Higher turnover isn't automatically better. Cutting inventory too aggressively can create more stockouts and lost sales.
A higher turnover number isn't automatically better if your fill rate is falling or lost sales are increasing.
Where to find it: Check your DMS turnover and aging reports. If your DMS doesn't provide turnover directly, a common annual calculation is:
Inventory turnover=Annual parts cost of goods sold÷Average inventory value at cost
For a monthly review, use a consistent rolling 12-month calculation rather than comparing a single month's turnover to an annual figure.
What to do with it: Review slow-moving parts alongside fill rate and lost sales. Look for stocking quantities that don't match actual demand.
6. Canceled and Unfilled Orders
How Many Sales Are Falling Apart Before They're Completed?
An order isn't a completed sale until the customer gets the part.
Cancellations can result from unavailable inventory, incorrect parts, delivery delays, or customers changing their minds.
Where to find it: Review DMS order status, special-order, and cancellation reports, along with any other systems where orders are processed.
What to do with it: Group cancellations by reason. If availability is the biggest issue, review stock accuracy and sourcing. If delays are driving cancellations, look at lead times and customer communication.
7. Repeat Customer Rate
Are Customers Coming Back?
Repeat customer rate helps you understand how often customers return to buy again. This is especially useful for wholesale accounts, where regular purchasing activity can tell you a lot about account health.
8 accounts didn't purchase this month. That doesn't mean they're lost, but it's worth finding out why.
If you see a decline from last month, it doesn't automatically mean you've lost those customers. Their demand may have changed. But it's a reason to follow up.
Where to find it: Review customer purchase history in your DMS or CRM. Use a longer repeat-purchase window for retail customers who buy less frequently.
What to do with it: Identify customers whose purchasing activity has slowed. Follow up to understand whether availability, pricing, service, or changing needs are affecting their orders.
What about the sales your reports can't see?
Your DMS shows you the business coming through your doors. But what about customers searching online for parts you carry who never find your dealership?
How much business are you missing simply because those online shoppers don't know you have what they need?
