Orchestration vs. Choreography

Question

What are the differences between service orchestration and service choreography from an intra-organization point of view.

Answer 1

Services can be distinguished between atomic services and services composed of other services. Such compositions are called "orchestration". Sometimes workflow, sometimes business process. For instance, BPEL is an orchestration language, but calls itself "business process execution language".

There is no requirement that services need to be hierarchically composed. That means, two services may talk to each other. The protocol running between them is called "choreography". It may be two services, but usually, there are more than two services involved. Each service in a choreography may be seen as orchestrator of the partner services. Each service taking part in a choreography may be realized as orchestration/workflow/process.

An orchestration shows the complete behavior of each service whereas the choreography combines the interface behavior descriptions of each service.

A good scientific article distinguishing choreography, interface behavior, provider behavior, and orchestration is the following one: Dijkman, R. & Dumas, M. Service-oriented Design: A Multi-viewpoint Approach International Journal of Cooperative Information Systems, 2004, 13, 337-368