Co-ordination of events in a process. Overlapping with the related concept of choreography, orchestration directs and manages the on-demand assembly of multiple component services, to create a composite application or business process. Orchestration tends to imply a single co-ordinating force, whereas choreography also applies to shared co-ordination across multiple autonomous systems. After evaluating several competing specifications, mainstream sentiment is now converging on BPEL4WS as the core standard for web services orchestration.