A customer orders; they are sent product as soon as possible, usually from stocked inventory (your Finished Products Store) or items that are quickly custom-built from waiting work-in-process. The customer is happy. The factory now has work to do to move the rest of the product forward to be ready for the next order. Additional finished product is made to replenish the store shelves. Any additional work-in-process is made to replenish the work-in-process store. Orders are placed to replenish the raw material store.