A presentation at BUSITAL 2010

1. Describing Coordination Services with REA Hans Weigand, BirgerAndersson, Paul Johannesson, Maria Bergholtz, JeewanieJayasingheArachchig Tilburg University Stockholm University

2. Assumptions Users often need to combine several services to fulfil their goals Coordination services are services, possibly implemented as web services, that support the coordination of (real-world) services To support users of a future Internet of Services, the effect of the coordination services must be described in such a way that users are not only able to discover services but also to detect and prevent possible conflicts in their composition

3. Application

4. users (or service composers addressing a particular user segment) compose mashups and interact with the widgets in them to access web services

5. The web service typically supports the coordination with a service provider who provides a real-world service as part of a service bundle

6. The service affects a resource that concerns the user (the resource could be the user himself, for instance in the case of a hotel reservation)

7. Research Goal A generic language to describe services, the resources they use, as well as planned and actual events. Web services can use this language to represent the pre-conditions and effects of the real services they connect to as well as their own semantics. Such a language is to be basedon the REA ontology.

8. Basic REA Ontology

9. CommitmentPattern(Decrement)

10. Reserve - Committing to Exchange a Resource

11. Service Exchange

12. Service Exchange The service is exchanged between agents in return for money

13. Service Exchange At the same time, the service is a resource produced in a conversion process at the provider

14. Service Exchange The service is consumed in a conversion process by the customer

15. Service Exchange The service is used in a conversion process by the customer

16. CoordinationObjects Reservations reduceuncertainty Purchase orders definewhat to exchange Appointments are parts of order fulfilments

17. CoordinationObjects

18. CoordinationObjects A purchase order is a commitment to deliver products

19. CoordinationObjects A reservation is a conditional commitment to establish a purchase order

20. From Web Services to Business Services