Know where things are

Start from the question, not the tag

Tracking projects go wrong when they start from a technology. The useful questions come first: what do you need to know about each item, how often, and who is standing next to it when you need to know? A box of fittings needs to be counted when it is received and when it is issued. A generator on a rental needs to be found on a site across the province. A pallet of steel needs to be identified at a gate without anyone climbing on it.

Those are three different jobs, and they usually call for three different tags. Most sites end up with a mix, chosen per kind of item.

QR codes and barcodes

Printed labels are cheap, reliable and easy to replace. A phone or a scanner reads them one at a time, with a line of sight. They suit anything a person handles anyway: receiving, picking, issuing, counting. Their weakness is the same as their strength: someone has to point a scanner at each label, so they do not tell you where something is unless someone scanned it there.

• Good for: warehouse bins, boxed stock, tools in a crib, documents and samples.
• Watch for: labels that fade, tear or freeze outdoors; choose industrial labels and printers where that matters.
• Hardware: label printers, scanners or rugged mobile computers, and labels and ribbons as a running cost.

Passive RFID

Passive UHF RFID tags have no battery. A reader energises them by radio and reads many at once, without line of sight, from a handheld or from a fixed reader at a gate or a dock door. That is what makes counting a shelf or recording everything that passes a gate possible without anyone scanning item by item.

RFID is also the technology most sensitive to its surroundings. Metal reflects the signal and liquids absorb it, so tags made for metal surfaces, careful reader placement and a site survey before any purchase are what separate a working system from a disappointing one.

• Good for: pipe and steel, returnable containers, tools that pass through a gate, inventory counts.
• Watch for: metal and liquids, tag placement, and readers placed where people and vehicles actually pass.
• Hardware: handheld and fixed readers, tags suited to the surface, and installation of fixed readers.

Active RFID and Bluetooth beacons

Battery-powered tags broadcast on their own, so gateways installed around a building can tell which room or zone an asset is in without anyone scanning. They suit valuable equipment indoors: carts, instruments, test gear. Batteries need replacing, and the gateways need power and a network connection.

GPS trackers

GPS trackers report their position over a cellular network, so they find things anywhere there is sky and signal: vehicles, trailers, generators, modules on a large site. They carry a data plan and a battery or a power connection, so they belong on items worth more than the tracker and its plan, and they work poorly indoors.

The software is what makes the tags useful

Tags only produce reads. The system around them turns reads into answers: what was received against which order, where an item was last seen, who has it, when it is due back, what is missing from a count. It also has to work where the items are, which often means a mobile app that keeps working offline and syncs later, and integration with the systems that already hold your orders, assets and accounts.

What keeps costing after launch

The hardware price is only the start. Labels and ribbons run out. Active tags and GPS trackers need batteries or power. GPS trackers carry a monthly data plan for as long as they report. Tags fall off, get painted over or leave with an item that was never returned. A realistic plan budgets for replacing a share of tags every year, and for someone whose job includes keeping the readers and gateways working.

The software has running costs too: hosting, support, and the small changes every operation needs once people start using a system for real. The worked examples below show hosting and support as monthly figures beside the build.

Counts, exceptions and trust

A tracking system earns trust the first time a count matches what is on the shelf. It loses it the first time it does not and nobody can say why. Design for exceptions from the start: items read in two places at once, items not seen for longer than they should be, counts that differ from the record. Each should land on a list with an owner, and closing it should leave a record of what was found.

What it costs, worked out now

The two worked examples below are priced by our estimator from the rate card in force when you open this page, hardware included from its catalogue: a single warehouse on QR codes and barcodes, and four yards mixing passive RFID on metal, GPS on large equipment and barcodes for the rest.

How to start

1. 01

   List the items and the questions

   For each kind of item: what you need to know, how often, and who is next to it.

2. 02

   Pilot one area

   One warehouse, one yard or one crew, with the tags that fit, before buying for every site.

3. 03

   Survey before ordering RFID

   Test reads on your real materials and layout before committing to readers and tags.

4. 04

   Connect it to what you run

   Orders, assets and accounts stay in your existing systems; tracking fills in where things are.