Looking for some opinions: If a company's structure only needs one of either Department OR Class....would you use only Department or only Class?

If your one use right now is for Cost Centers, I'd use Departments since that's what they’re meant for. If it's not for Cost Centers, I'd use Class since the company may eventually want to use Cost Centers. It's not a huge deal to use Class for that later instead since Departments and Classes are functionally identical for the most part, but that's best practice