Actionrefinementforreal-timeconcurrentprocesseswithurgentinteractionsisstudied,whereapartial-ordersetting,i.e.,timedbundleeventstructures,isusedasthesystemmodelandareal-timeLOTOS-likeprocessalgebraisusedasthespecificationlanguage.Itisshownthattheproposedrefinementapproacheshavethecommonlyexpectedproperties:(1)thebehaviouroftherefinedprocesscanbeinferredcompositionallyfromthebehaviouroftheoriginalprocessandfromthebehaviouroftheprocessessubstitutedforactions;(2)thetimedextensionsofpomset(partiallyorderedmultiset)traceequivalenceandhistorypreservingbisimulationequivalencearebothcongruencesundertherefinement;(3)thesyntacticandsemanticrefinementscoincideuptotheaforementionedequivalencerelationswithrespecttoacpo-baseddenotationalsemantics.
