Toward Web Services Choreography
W3C Web Services Choreography
March 2003

Introduction
As a consumer of Web Services technology, we see four problems to be solved by the working group:
Sticky policies
Web Services processing model
Orchestration
Interoperability
An effective solution requires a framework for managing composite services

Sticky Policies
How do we handle metadata across multiple services?
Called sequentially
Called across organization boundaries
Assert(AÇBÇC>1)
Do we need an outside controller to manage the assertions?

Processing Model
 When request is submitted to a Web Service, what kinds of processing on data contained in request are acceptable, given the next stop in the chain is unknown at initial call?

Orchestration
Managing conditionals, routing of information through the system
Syntactic wrapper with conditionals?
Undefined relationship between orchestration and choreography
Appropriate constraints
Data path
Maintaining enough intelligence in the request that it can navigate through the system
Practical limits on nodes in call chain?

Interoperability
Transport-level interoperability is assumed
At organizational level
Guarantee messages from A to B can be executed by B (semantic level)
Information must have common meaning across services

Summary
Our challenge is to develop a framework for managing composite Web Services
Across platforms
Across vendors
Across languages