Your local grocery store carries shelves full of items so they are ready to be purchased as soon as you walk in the door. Shelves are restocked according to what gets sold, with the goal of always keeping a few items on the shelf. If there is too much inventory, the store needs a huge space and risks products expiring before they sell. Too little inventory, and the items will sell out leaving an empty store where no one wants to shop. By stocking a small inventory and replacing items according to sales, the store stays in business. Your studio should take the same approach to stocking and restocking inventory for sale.