Yes, this is EXACTLY how I run my business. Each major piece of gear is purchased with a planned life expectancy. It's different for different types of gear. Eg, a pice of trussing is going to have a longer life in the warehouse than a mixer, but each will be inventoried with a set number of shows that it is budgeted to be on before replacement.
This allows me to more accurately track the costs of gear and allows me to sell gear and replace with newer tech more often. Since the product gets moved when it still has a decent resale value, the cost between doing that and running it into the ground isn't necessarily as different as one might think.