Do you have a system for wholesale reorders, or is it all gut feel?

I've been thinking about this a lot lately. It's easy to know when something's obviously not working, but the middle ground is tricky, like when a brand sells okay but not great, or when you love the product but the MOQs are tough on cash flow.

Do you have a threshold you stick to (sell-through rate, turnaround time, etc.), or do you mostly go on instinct? Would love to know what's actually working for people running physical or online retail.