Whether barcodes are worth it at your size
Scanning removes a category of human error entirely. The question is whether that error is currently costing you enough.
Barcode scanning eliminates transcription error at the point of picking, receiving and counting. It is the single largest available improvement in stock accuracy, and it is not free.
Digital activity data can supplement, but not replace, process measures. For a workplace example of PC-level activity tracking, see this article.
What it actually removes
The errors it removes are specific: picking the wrong item because two look similar, typing a code incorrectly, counting the wrong line, and receiving against the wrong item.
It does not remove miscounts of quantity, unrecorded movements, or anything caused by process rather than identification. Businesses that expect it to fix everything are disappointed by the half it cannot touch.
The strongest case is a catalogue with many visually similar variants. Where items are visually distinct and few, the gain is much smaller.
The cost is mostly labelling
Hardware is cheap and the ongoing work is applying and maintaining labels — particularly for items that arrive without a usable barcode, or where the supplier's barcode covers a case rather than a unit.
For technical background on product identification and scanning, GS1 barcode standards describe common barcode standards used in supply chains.
Estimating this properly before committing is what determines whether the project finishes. Half-labelled stock is worse than none, because scanning becomes unreliable and people revert to typing.
Use the supplier's barcode where you can
Most manufactured goods carry one. Recording it against the item — so a scan of the manufacturer's code finds your record — avoids relabelling entirely for a large share of the catalogue.
This requires capturing the barcode at receiving, once, per item. It is a small habit with a large cumulative effect.
Label locations too
Scanning an item confirms what. Scanning a location confirms where, and putaway and picking errors are largely location errors.
Location labels are cheaper than item labels — there are far fewer of them — and they frequently deliver more of the benefit.
Start with counting
Where the full project is too large, scanning during cycle counts alone is a contained first step: no change to daily process, immediate improvement in count speed and accuracy, and a realistic test of whether the labelling burden is manageable.