Label Them !!. To keep an account of all your assets be it machinery, equipment, fixtures, furniture, tools, electronic equipment, PC's and all those in your asset inventory.
Bar Coded, Serial Numbered, QR Coded any way you want.
On Aluminum riveted to the asset or polymers pasted on to the asset, however convenient to your kind of environment.
Small or tiny sized or combinations of sizes and substrates, any way which helps.