Service composition

Web services are subject to the same re-use requirements as any other 
software paradigm. This means that it must be possible to combine old 
services to make new ones:

D-AG008
The Web services architecture must provide a framework for effective 
re-use of existing services

Critical Success Factors for this goal:

AC025, AC024

D-AC025 ensures that services can be composed to form new services

D-AC025.1 It must be possible to express the composition of services and 
service interactions using XML artifacts
D-AC025.2 It must be possible to compose services dynamically, on the 
fly, as well as statically.
D-AC025.3 The service composition model must permit the expression of 
and the evolution of composed relationships
D-AC025.4 It must be possible to express sequencing of services, 
predicate priorities between services, and the flow of information 
between services
D-AC025.5 It must be possible to express delegation and nesting of 
service composition and sequencing.
D-AC025.6 It must be possible to model implicit transitions (such as 
abandoned conversations)
D-AC025.7 It must be possible for third parties to verify performance of 
services (where performance includes results as well as timeliness)

Received on Tuesday, 25 June 2002 20:13:38 UTC