A seat belt manufacturer estimates the demand for replacement seat belts and then creates a plan to manufacture those seat belts over a period of time. Once replacement seat belts start to roll off the production line, they are packaged into boxes (for the purposes of this example, let's assume 100 replacement seat belts per box) and sent to distributors in priority order of where it is anticipated the highest demand will be. These distributors then send the replacement seat belts to the car dealerships, who hold several in stock so that when a customer comes in requiring a replacement seat belt, they are able to replace it within a short period of ti