Fortune 500 In-plants

It's rather telling that the number one company on the Fortune 500, Wal-Mart, also maintains one of the largest, busiest in-plants in the country.

To find out just how important some of these Fortune 500 companies feel their in-plants are, IPG talked with eight of them, focusing on the insurance, retail, airline and oil industries. Here's why these companies feel it is so important to have an in-plant.