A system for controlling an engagement operation between first and second movable machines includes a separation sensor, a relative speed sensor and a controller. The separation sensor determines a separation distance between the first and second machines. The relative speed sensor determines a relative difference in speed between the first and second machines. The controller determines the separation distance between the first and second machines, decelerates the first movable machine when the separation distance is within a deceleration zone, determines a relative difference in speed between the first and second machines, and generates an engagement speed command to operate the first movable machine at a first ground speed equal to a second ground speed of the second movable machine plus a relative engagement speed when the separation distance is within a buffer zone.