My answer to Which department to work to gain the most benefit if I want to open my own business?
Answer by Ken Larson:
Ask for assignments that rotate you through the various support units of the company leading to project or product management, which crosses all departments and runs individual company services or product lines.
Most big companies have either internship programs or career development paths that give this type of exposure to promising project or product development management professionals.
I think you can understand how the above background would prepare you to run your own business – given a broad base of what it takes to operate an enterprise.