Orchestration is the ability to control operational flows and activities based on business rules, especially in multi-application systems complicated enough to require middleware such as ESB (“Enterprise Service Bus”) or the older MOM (“Message-Oriented Middleware”).
In the context of a file transfer system, orchestration often refers to the ability to apply automation such as triggers, schedules, explicit calls and chained calls to model or solve a business problem.
In the context of SOA (“Service Oriented Architecture”), orchestration typically refers to the ability of programmers to rapidly develop composite applications due to the fact that most available application APIs have been encapsulated and published in reliable directories that programmers’ applications can easily interpret and use.
BEST PRACTICE: Orchestration typically invokes an image of “drag and drop” business application development: a task easy enough for the average business analyst. Reality often requires more than that: shelling out to scripts, editing raw XML documents by hand and having to clean up “orchestrated code” after an incompatible interface is rolled out are still common issues.