The ever increasing complexity of manufacturing systems demands for new real-time control infrastructures. With the new standard IEC 61499 the IEC introduced a base for such a control infrastructure. An open issue of this standard is the missing definition of real-time execution. This work maps existing real-time execution theory to IEC 61499 execution elements deriving the basic element for the new execution approach-the event chain concept. A novel execution environment for an efficient execution of reconfigurable real-time control in IEC 61499 is presented.