How to Track Back-Bar Product Usage When Two Beauty Rooms Share Supplies

In a small beauty studio, two treatment rooms shared the same back-bar products. Inventory looked fine at the start of the week, but by Friday one serum was almost gone and nobody knew which service used it. Reordering became guesswork, and pricing was hard to review because product cost per treatment was invisible. I made the tracking simple enough that staff would actually use it. Each room…