There are a number of different approaches to inventory management, which work for different business types. You may choose just in time (JIT) inventory management if it's important to you to keep as low a stock holding as you can at any given time. Or, you may choose an economic order quantity (EOQ) approach if you want to balance out ordering so you don't end up ordering new supplies too often. Different approaches are out there to suit manufacturing companies, too - doing some research into the principles behind inventory management is a good way to decide which method suits your needs.