1. A system comprising, an optimizer which, if executed, instructs at least one processor to determine a distribution of successive operations among a plurality of execution environments based on a presumed status of the execution environments so as to achieve a performance objective; a scheduler which, if executed, instructs at least one processor to determine whether an actual status of the execution environments renders the distribution suboptimal for achieving the performance objective and to request an alternative distribution, when it is determined that the actual status renders the distribution suboptimal; and a dispatcher which, if executed, instructs at least one processor to ensure the successive operations are executed in a predetermined order.