Last month, REL Consulting published their 2013 working capital survey in CFO magazine. The 1,000 large U.S. companies included in the survey had more than $1.1 trillion in excess working capital. Given the recent attention to large cash balances, this is not surprising.

It is more surprising that 43 percent of the excess working capital is tied up in inventory. Net working capital increased 6 percent over the past year, and has increased 25 percent in the past three years.

Only 16 companies in the 1,000 were able to avoid a 5 percent decrease in efficiency over the past three years in at least one of the important metrics: day's sales outstanding, day's inventory outstanding, or day's payable outstanding.

Some of the better performers in day's working capital outstanding include Linn Energy (negative 63 days), Noble Energy (negative 54 days), Dell (negative 22 days), and Apple (negative 22 days).