The Electronic Control Unit (ECU) can be modified/reprogrammed, a common term for this is 'Chipping'. You may be thinking of adding such a modification to your vehicle to improve it's performance. It is recommended you go to your local Ford dealership to have any modifications.
Ford Motor Company advise against going to independent organisations as interference with a vehicles programming could have negative effects and could void any warranty if it was found to be the cause of any vehicle issue. By going to your local dealership you have the peace of mind that a Ford approved engineer will be looking at your vehicle.