Contracts, SLAs and Virtual Enterprises

1. Contracts, SLAs and Virtual Enterprises Carlos Molina-Jimenez (Carlos.Molina@ncl.ac.uk) Meeting of TAPAS partners at University of Newcastle upon Tyne 5-6th Aug 2002

2. Useful notation to remember • E: Enterprise • VE: Virtual Enterprise • SLA: Service Level Agreement • RO: Rights and Obligations • Cli: Client • Srv: Server • ASP: Application Service Provider

3. Outline of the presentation • Motivation for this presentation • What is a virtual enterprise? • What is a contract? • Contracts in virtual enterprises • What is a SLA? • Relationship between SLAs and contracts? • Conclusions • References

4. Motivation for this presentation • Strong relation between contracts, virtual enterprises and server level agreements. • Understanding ASP, marketplaces, etc. SLA Contracts and VE

5. How is a VE created? Purpose • -Two or more enterprises • Possibly mutual distrust • Business relationships • Provision of resources to • each other: • electronic and mechanical • components. • cars, ships, computers • and other machinery. • IT, marketing services, etc. What is a virtual enterprise?

6. Shared resources Private resources Efficient provision means sharing VE E1 E2 Private resources Shared resources

7. VE Shared resources E1 Private resources E2 Private resources Virtual enterprise: logical view

8. How are disputes prevented? A mechanism to regulate interactions between participating parties is needed. A contract

9. AGREEMENT Rights Rights Alice Bob Obligations Obligations Alice Bob Signatures Manager E1 Manager E2 What is a contract? • A contract between Alice (the manager of E1) and Bob (the manager of E2) is:

10. Non-computational computational We did not invent contracts • Have been around for ages. • Used in different situations. • However: Our interest focuses on contracts where the provision of services (resources) heavily depends on the use of computer technology. • These contracts have:

11. Computational part of contracts • We conceive a contract as • A script file (with readable text and executable lines) that can be enacted. • Digital signatures, • Cryptography, other computer technology. • Focus on • enactment • monitoring • renegotiation of parts. • Further research • original negotiation • dispute resolution (in court) done remotely and automatically from the original script file.

12. AGREEMENT Rights Rights Alice Bob Obligations Obligations Alice Bob Signatures Manager E1Manager E2 Relevance of contracts in VEs. • A contract enactment creates a VE. Private resources E2 VE Shared resources enactment Private resources E1

13. Bob Alice Rights: to request Doc1. Obligations: not to submit requests on weekends Rights: to check that request was submitted on Mon-Thu Obligations: to provide a copy of Doc1 in less than 24 hs. Example of a contract • “Alice has the right to retrieve a copy of doc1 from Bob’s enterprise, provided that her request is not submitted on Fri, Sat or Sun. Bob has the obligation to provide doc1 in less than 24 hs.” • Rights and obligations:

14. Contract monitoring architecture Bob’s E2 Alice’s E1 contract monitor request (doc1) Cli Srv check Alice’s ROs check Bob’s ROs reply (doc1) Srv request (doc2) Cli check Bob’s ROs check Alice’s ROs reply (doc2) E-Enterprise, ROs- Rights and Obligations, Cli-Client, Srv-Server

15. ASP (adesso) SLA Client Definition of SLA • “A service level agreement defines the responsibilities of a service provider and the user of that service. It also identifies the services provided as well as the supported products, measurement criteria, reporting criteria, and quality standard of the service” [ Beckman and Oleneva,2002]. • SLAs are needed where two (or more) enterprises interact: • * for ex. between an ASP (Adesso) and a client.

16. Alice AGREEMENT ABOUT Bob SLA={R1,O1,…Rm,Om,} Accurate definition of SLA • Accurate definition of SLA: • agreement about some specific QoS of interest to Alice and Bob. • defined as a set of named clauses about rights and obligations. For ex. R1- Alice has the right to request Doc1. O1- Alice has the obligation not to submit a request on weekends. R2- Bob has the right to check that the request was submitted on Mon-Thu. etc. Can name can change RO- Rights and Obligations

17. Service level agreements and rights and obligations • Alice and Bob interaction is defined and regulated by their Rights and Obligations (ROs). • ROs can be named and grouped into SLAs: • SLA1={R1,O1,…Rm1,Om1}, SLA2={R1,O1,…Rm2,Om2}, SLA3={R1,O1,…Rm3,Om3}, … … …

18. AGREEMENT SLA1={R1,O1,…Rm1,Om1}, SLA2={R1,O1,…Rm2,Om2}, SLA3={R1,O1,…Rm3,Om3}, … … … Signatures Manager E1 Manager E2 SLAs and contracts • A SLA is not a contract. • A contract can be defined in terms of named SLAs: Named SLAs and RO can be: referred, edited, changed.

19. ASP (adesso) ASP (adesso) SLA Client Client Conclusion • We need to specify the interaction between two or more enterprises not in terms of SLAs but in terms of contracts enactment of the contract creates a VE

20. References • Toward an e-contract management architecture for inter-organizational interaction in TAPAS … John Warne, 2002

21. Conclusions (more) • No business interaction between two or more enterprises can happen without a contract. • A SLA is not contract but can be part of a contract. • SLAs list the ROs for a speficic QoS. • A contract that precisely lists and names SLAs (and ROs) can be automatically • enacted to create a VE. • monitored.

22. Shared resources Private resources Virtual enterprise: physical view VE E1 E2 Shared resources Private resources

23. Definition of an electronic contract A digitally signed statement of all qualified named entities involved, detailing roles, rights, and obligations for client/server and peer/peer use of services/resources in a Virtual Enterprise (VE).

24. Contract monitoring architecture Bob’s E2 Alice’s E1 contract monitor request (doc1) Cli Srv check Alice’s RO check Bob’s RO reply (doc1) Srv request (doc2) Cli check Bob’s RO check Alice’s RO reply (doc2) E-Enterprise, RO- Rights and Obligations, Cli-Client, Srv-Server