Truck stock and parts inventory: what to carry and what's dead weight

I see the same two mistakes over and over. One shop sends techs out with a nearly empty van, so every third call turns into a supply house run and a callback the next day. The other shop lets trucks fill up with parts nobody has pulled in a year, and that is cash sitting on a shelf instead of in the bank. Truck stock is a balance, and getting it right shows up directly in your close rate and your margin.

Why truck stock is a profit lever

Every trip back to the distributor costs you a full labor hour or more, and it usually means the customer waits another day for a fix they wanted done today. A well-stocked truck lets a good tech diagnose and repair in one visit far more often, which is the single biggest driver of first-time fix rate. That number matters more than almost anything else in a service business: it drives reviews, referrals, and repeat calls, and it is worth building your stocking decisions around.

Build a core list, then a job-specific list

Split your stock into two buckets. The core list is what every truck carries all the time: common capacitors, contactors, relays, igniters, thermostats, a range of motors for the equipment you service most, refrigerant, filters, and basic tubing and fittings. Build this list from your own dispatch history, not from a generic checklist. Pull a year of work orders and see what actually gets used on the calls you run most.

The job-specific list is what a tech pulls from the shop or a distributor for a scheduled install or a known repair. Do not try to carry install-grade equipment on every truck. That is what min/max stock at the shop and a good relationship with your distributor are for.

Set min and max levels, not guesses

Give every core part a minimum quantity that triggers a reorder and a maximum that stops a tech from overloading the van “just in case.” Without a max, trucks quietly accumulate weight and clutter, and that clutter is where dead stock hides. A simple par system, checked on a set restock day each week, beats leaving it to memory.

Track it without overbuilding the system

You do not need a warehouse-grade system to run this well. If you already use field service software, check whether its inventory module can tie parts to work orders, since that data tells you which items actually earn their spot on the truck. If you are not there yet, a shared spreadsheet with min/max columns and a weekly count is enough for most independent shops. The goal is visibility, not complexity.

Audit for dead stock on a schedule

Every quarter, pull the list of parts that have not moved. Some of that is fine to hold if it is cheap and occasionally critical. The rest should go back to the distributor if your account allows returns, get used on a project where it fits, or get written off so it stops distorting your numbers. Dead stock is not just wasted cash, it is also the clutter that slows a tech down when they are digging for the part they actually need.

Treat your truck stock list as a living document. Revisit it whenever you add a new equipment line, whenever a part shows up on repeat backorder, and at least twice a year even if nothing has changed. The shops with the best first-time fix rates are not the ones with the fullest trucks. They are the ones who stock on purpose.