QoS Assessment of Providers with Complex Behaviours: An Expectation-Based Approach with Confidence

  • Gareth Shercliff
  • Jianhua Shao
  • W. Alex Gray
  • Nick J. Fiddian
Part of the Lecture Notes in Computer Science book series (LNCS, volume 4294)


Service Level Agreements (SLAs) define a set of consumer expectations which must be met by a provider if a contract is not to be broken. Since providers will potentially be providing many different services to thousands of different consumers, they must adopt an efficient policy for resource management which differentiates consumers into service ranges. Existing approaches to QoS assessment of providers assume that the policy of a provider with respect to consumers is handled on an individual basis. We maintain that such approaches are ineffective when providers adopt a policy based on service differentiation and in response introduce and evaluate an expectation-based approach to QoS assessment which presupposes the classification of consumers into ranges defined by their expectation. As well as carrying out assessment to determine the likely future behaviour of a provider for a given consumer expectation, we attach a confidence value to our assessment to indicate the level of certainty that the result is accurate. Our results suggest that our confidence-based approach can help consumers make better informed decisions in order to find the providers that best meet their needs.


  1. 1.
    Al-Ali, R.J., Rana, O.F., Walker, D.W.: G-QoSM: Grid Service Discovery Using QoS Properties. Journal of Computing and Informatics (2003)Google Scholar
  2. 2.
    Dan, A., Davis, D., Kearney, R., King, R., Keller, A., Kuebler, D., Ludwig, H., Polan, M., Spreitzer, M., Youssef, A.: Web Services on Demand: WSLA-Driven Automated Management. IBM Systems Journal, Special Issue on Utility Computing 43(1), 136–158 (2004)Google Scholar
  3. 3.
    Deora, V., Shao, J., Gray, W.A., Fiddian, N.J.: A Quality of Service Management Framework Based on User Expectations. In: Orlowska, M.E., Weerawarana, S., Papazoglou, M.P., Yang, J. (eds.) ICSOC 2003. LNCS, vol. 2910, pp. 104–114. Springer, Heidelberg (2003)CrossRefGoogle Scholar
  4. 4.
    Deora, V., Shao, J., Gray, W.A., Fiddian, N.J.: Expectation based quality of service assessment. International Journal on Digital Libraries (2006) (to appear)Google Scholar
  5. 5.
    Kalepu, S., Krishnaswamy, S., Loke, S.W.: Reputation = f(User Ranking, Compliance, Verity). In: Proceedings of the IEEE International Conference on Web Services (ICWS 2004). IEEE Computer Society, Los Alamitos (2002)Google Scholar
  6. 6.
    Levy, R.M., Nagarajarao, J., Pacifici, G., Spreitzer, M., Tantawi, A.N., Youssef, A.: Performance Management for Cluster Based Web Services. In: Goldszmidt, G.S., Schönwälder, J. (eds.) Integrated Network Management. IFIP Conference Proceedings, vol. 246, pp. 247–261. Kluwer, Dordrecht (2003)Google Scholar
  7. 7.
    Ludwig, H.: Web Services QoS: External SLAs and Internal Policies or: How do we deliver what we promise? In: Fourth International Conference on Web Information Systems Engineering Workshops (WISEW 2003), pp. 115–120 (2003)Google Scholar
  8. 8.
    Maximilien, E.M., Singh, M.P.: Toward Autonomic Web Services Trust and Selection. In: ICSOC 2004: Proceedings of the 2nd International Conference on Service Oriented Computing, pp. 212–221. ACM Press, New York (2004)CrossRefGoogle Scholar
  9. 9.
    Menasce, D.A.: QoS Issues in Web Services. IEEE Internet Computing 6(6), 72–75 (2002)CrossRefGoogle Scholar
  10. 10.
    Ramchurn, S.D., Hunyh, D., Jennings, N.R.: Trust in Multi- Agent Systems. Knowledge Engineering Review (2004)Google Scholar
  11. 11.
    Sahai, A., Ouyang, J., Machiraju, V., Wurster, K.: BizQoS: Specifying and Guaranteeing Quality of Service for Web Services through Real Time Measurement and Adaptive Control. HPL-2001-134. Technical report, HP Labs (2001)Google Scholar
  12. 12.
    Sherchan, W., Krishnaswamy, S., Loke, S.W.: Relevant Past Performance for Selecting Web Services. In: QSIC 2005: Proceedings of the Fifth International Conference on Quality Software, Washington, DC, USA, pp. 445–493. IEEE Computer Society, Los Alamitos (2005)Google Scholar
  13. 13.
    Shercliff, G., Shao, J., Gray, W.A., Fiddian, N.J.: A Multiple Quality-Space Mapping Approach to Qos. In: CIT 2006: Proceedings of the Sixth IEEE International Conference on Computer and Information Technology. IEEE Computer Society, Los Alamitos (2006) (to appear)Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2006

Authors and Affiliations

  • Gareth Shercliff
    • 1
  • Jianhua Shao
    • 1
  • W. Alex Gray
    • 1
  • Nick J. Fiddian
    • 1
  1. 1.School of Computer ScienceCardiff UniversityUK

Personalised recommendations