How much inventory should I be carrying at any point in time? Managing inventory levels is arguably the most difficult challenge for any retailer, music retailer or otherwise. The challenge stems from many unpredictable factors, including having to guess what your customers will ultimately buy, unexpected downturns in the economy, real estate and the stock market, changes in technology, erratic manufacturing and product availability, high purchase requirements by suppliers with coveted product lines, and a general lack of prudent inventory management knowledge by many retailers.