We study directed control of discrete event system expressed as the parallel composition of interacting automata. Solutions
that first compose the automata and then compute a controller may result in an exponential blow up. We present a technique
that builds the composition on-the-fly guided by a novel domain-independent heuristic, which attempts to discover relevant
dependencies between the intervening components. We obtain safe and non-blocking directed controllers, or directors, exploring
a reduced portion of the state space. We present the first experimental results on directed control comparing on-the-fly
composition with informed search against the original monolithic approach to directed control.