Field Service Inventory Management: Stop Losing Jobs to Missing Parts

A tech arrives on site, diagnoses the problem in ten minutes, and then realises the part they need is on another van across town. Now you’ve got a return visit to schedule, a frustrated customer, and a tech who’s wasted half an hour for zero billable output. Multiply that by three or four times a week across your team, and you’re looking at thousands of dollars in lost productivity every month.

The root cause isn’t lazy techs or bad luck. It’s inventory blindness. Most field service companies have no real-time picture of what’s on each van. Parts get used and not logged. Stock gets borrowed between vehicles in the car park and never recorded. Reorders happen when someone notices the shelf is empty — which is usually one job too late.

The Real Cost of Poor Van Inventory

Missing parts don’t just cost you a return trip. They cost you in ways that don’t show up on a single invoice:

• Second truck rolls. The obvious one. Fuel, labour, and scheduling overhead to send a tech back for a job that should have been completed the first time.
• First-time fix rate. Every incomplete visit drags this metric down, which affects customer satisfaction, technician morale, and your ability to win contracts with commercial clients who measure it.
• Overstocking. Without data on actual usage, most techs hoard parts they rarely need “just in case.” That’s capital sitting in a van doing nothing — and it adds up fast across a fleet of ten or fifteen vehicles.
• Emergency orders. When you run out of a common part, you’re paying express freight or buying retail from the local supplier at double the wholesale price. A $12 capacitor becomes a $35 capacitor because nobody flagged the reorder point.

What Good Van Inventory Looks Like

At its core, van inventory management means knowing three things at all times: what’s on each vehicle, what’s being used, and when to reorder.

Per-Van Stock Lists

Every vehicle should have a defined standard loadout — a list of parts that van should always carry, based on the types of jobs that tech typically handles. A residential AC tech’s van looks different from a commercial refrigeration tech’s van. The loadout should reflect the work, not a one-size-fits-all approach.

When a tech uses a part on a job, they log it against the job. The system deducts it from that van’s inventory. At the end of the day — or in real time if you’ve got the right system — you can see what each van is carrying, what’s been depleted, and what needs replenishing.

Reorder Points

For every part in your system, set a minimum quantity threshold. When stock hits that level, an alert fires. Not an alert that someone has to remember to check — an automatic notification to whoever handles ordering.

The reorder point isn’t the same for every part. A capacitor you use ten of per week has a different threshold than a compressor you use one of per month. Base it on usage rate and supplier lead time. If a part takes five business days to arrive and you use three per week, your reorder point needs to be at least fifteen — with a buffer for spikes.

Stock Transfers Between Vehicles

This is where most manual systems completely fall apart. Tech A needs a part that Tech B has. Tech B leaves it on the dashboard at the depot. Tech A picks it up next morning. Nobody records the transfer. Now your inventory shows Tech B has a part they don’t have, and Tech A has a part the system doesn’t know about.

A proper system makes transfers trackable. Tech B scans or logs the part as transferred. Tech A confirms receipt. The inventory moves from one van to another in the system — just like it moved physically. Simple in concept, but it requires a process your team will actually follow.

From Spreadsheet to System

Most companies start van inventory management with a spreadsheet. Tech names across the top, parts down the side, quantities in the cells. It works for about a month. Then people stop updating it, the numbers drift, and within a quarter it’s fiction.

The spreadsheet fails because it’s disconnected from the work. The tech finishes a job, does their paperwork, and is supposed to also update a separate inventory spreadsheet. It’s an extra step with no immediate payoff for them — so it gets skipped.

The solution is to embed inventory into the job completion workflow. When the tech logs what they did on a job, the parts they used are captured at the same time. No separate step. No extra spreadsheet. The inventory updates as a byproduct of closing the job. This is the difference between a system techs tolerate and one they actually use.

The Warehouse Connection

Van inventory doesn’t exist in isolation. Parts flow from suppliers to your warehouse (or storeroom, or that corner of the shed), then from the warehouse to vans. If your warehouse inventory is a mess, your van inventory will be too.

The full picture looks like this: supplier delivers to warehouse, warehouse stocks are updated, van restocking pulls from warehouse, warehouse reorder triggers when its own stock drops below threshold. It’s a chain — and every link needs tracking.

For companies running ten or more vehicles, this gets complex enough that a manual system becomes a full-time job. That’s often the tipping point where a proper inventory system — whether off-the-shelf or custom-built — starts paying for itself in reduced stockouts and lower carrying costs.

Where to Start

If you’re currently tracking nothing, don’t try to inventory every part on every van in one go. Start with your top 20 parts — the ones your techs use most frequently and the ones that cause the most return visits when they’re missing.

Build a standard loadout for each van using those 20 parts. Set reorder points based on your best estimate of weekly usage. Track usage for one month, then adjust. You’ll be surprised at the gap between what you thought techs were using and what they actually use.

Once you’ve proven the process with 20 parts, expand. Add the next tier. Then the next. Within a quarter, you’ll have a functioning inventory system — and the data to prove it’s working, because your truck rolls for missing parts will have dropped measurably.

The goal isn’t warehouse-grade precision. It’s knowing enough about what’s on each van to stop the preventable failures — the return visits, the emergency orders, the jobs that should have been completed in one trip but took two.