If business is on going.
Each device/equiment should have a life cycle.
So each year you have purchased new one.
Some old one retired(sold) after 3-5-10 years.
1. Yes, you need keep track them.
2. You need select a formula on how to depreciate.
3. first-year can only claim 50% of what from the formula.
4. Last retire year can claim all remaining (if any left).
