Linked USDL Agreement is a Linked Data based semantic model to describe, share on the Web, and automatically process service agreements This presentation describes the model, its design process and tooling support. Presented at IEEE International Conference on Web Services (ICWS) 2015. Part of Linked USDL family. Find out more at https://github.com/linked-usdl/usdl-agreement Try out a demo at: http://www.isa.us.es/IDEAS/Linked_USDL_Agreement/

1. 22nd IEEE International Conference on Web Services – ICWS 2015
Effectively Sharing Semantic Service Level Agreements
on the Web
Linked USDL Agreement
José María García, Carlos Pedrinaci, Manuel Resinas, Jorge
Cardoso, Pablo Fernández, Antonio Ruiz-Cortés

2. Outline
• Introduction
• Use Case
• Linked USDL Agreement
• Evaluation and Tooling
• Conclusions and Future Work
2

3. Introduction
• Service market is growing
• Service descriptions are available
• But…
3

4. Challenges on SLA descriptions
• Limited support to Quality of Service (QoS) and
Service Level Agreement (SLA) descriptions
• Existing SLA models problems
 Main focus was on technical, WS-* services
 No shared meaning of the content
 Not shareable on the Web
 Limited tooling support 4

5. Requirements for our solution
• Extension to Linked USDL
 Linked Data based model to describe various aspects of
services
• Lightweight schema
 Easy to use & understand
• Promotes sharing
 Following Web/Linked Data principles
• Support automation for Service Level Management
 Available tools
• Evaluated with real use cases
 Cloud Computing scenario
5

6. Use case driven design
• Use case scenario on cloud computing
• Competency questions need to be answered by our
model
• Taking into account existing SLA models
• Additional scenarios, such as software consultancy
contracts
6

7. Competency Questions (I)
• Which functionality and quality levels does a service provide?
7

8. Competency Questions (II)
• Which service properties are guaranteed to have certain
values?
8

9. Competency Questions (III)
• Which compensation will a user obtain if the
guaranteed value of some property is not provided?
9

10. Competency Questions (IV)
• Who is responsible for enforcing the guaranteed values?
10

11. Competency Questions (V)
• Who is responsible for monitoring and computing the
guaranteed values?
11

12. Competency Questions (VI)
• What is the assessment period while a guarantee is
provided?
12

13. Competency Questions (VII)
• How service property values are computed?
13

14. Linked-USDL Agreements model
14

15. Agreement Terms (CQ1, CQ2, CQ3)
15

16. Services and Entities Modeling (CQ4, CQ5)
16

17. Agreement Conditions (CQ1, CQ2, CQ6, CQ7)
17

18. Evaluation
18
• 13 out of 22 criteria
• The rest are not shared
by many approaches
• Not used in real world
SLAs
• Some criteria can be
covered by extensions

19. Tooling support
19

20. Validity Checking
20

21. Answering competency questions
21

22. Answering competency questions
22

23. Conclusions and Future Work
• Extension to Linked USDL to capture SLAs
• Good coverage of SLA lifecycle
• Extensible
• Future work
 Improve the tooling with more operations
 Implementation of a service marketplace based on Linked
USDL
23

24. Useful resources
• Linked USDL
 http://www.linked-usdl.org/
• Model and use cases
 https://github.com/linked-usdl/usdl-agreement
• Demo
 http://www.isa.us.es/IDEAS/Linked_USDL_Agreement/
24

25. 22nd IEEE International Conference on Web Services – ICWS 2015
Effectively Sharing Semantic Service Level Agreements
on the Web
Linked USDL Agreement
José María García
josemgarcia@us.es @josemgarcia_us
Thank you for your attention!