Introduction to Web Services Quality Model And Collaboration Issues for EERP

1. Introduction to Web Services Quality Model And Collaboration Issues for EERP 2007.12.12 Sojung Kim WSQM TC National Information society Agency

2. A table of contents • Critical Issue in SOA • WSQM • WS-Quality Factor • Next Step • EERP & WSQM

3. Critical Issues in SOA • Service Quality Issues have gained attention in SOA paradigm • SOA Governance : stakeholders’ role and responsibility • Different Service Life Cycle and a variety of stakeholders • Service Acquirer/Developer/Consumer, Quality Information Provider, Quality/Assuror/Authenticator/Manager • Role of service registry and responsibility for guaranteed service • What EERP wants • To build freestanding value networks in SOA • Deal with traditional but critical issues – Quality of Services effectively • WSQM provides • From well known system information quality to business value quality

4. WSQM TC • Overview • To prepares a quality model in the context of contracting for Web services between associates conceptually, in order to secure Web services at a specific level of service quality • Scope • To specify an overall model of quality of Web services in WSQM TC, It will include specified quality factors, associate roles, and activities

5. WSQM TC : Background & Needs • Requirements for definition of Service Quality according to Web Service proliferation • Motivation for activating quality activity of Web service associates • To help to make consensus between Web Service associates • ex) negotiation/contracts

6. WSQM • A model for configuring Web service quality or differentiating service level • It consists of 3 components: Quality Factor, Quality Associate, and Quality Activity. • Quality Factor: fundamental components that recognize Web services quality as the target for control. • Quality Associates: roles or tasks of the organizations or persons related with Web services. • Quality Activity: various actions performed by associates

7. WSQM : Quality Activities • Example of Quality Activity • Development Quality Contract: • between Stakeholder and Developer • Delivery time, Interoperability, Usability, Security • Management Quality Contract: • between Provider and Quality Manager • Manageability, Composability Development Quality Contract ServiceDeveloper ServiceDevelopment Service stakeholder Service Operation & Management ServiceProvider ServiceBroker Service Quality Contract Management Quality Contract ServiceConsumer Quality Manager Service user 7

8. WS-Quality Specifications Family WS-Quality Use Case v1.0 WS-Quality Test Guideline v1.0 WS-Quality Factor v1.0 WS-Quality Description Language v1.0 WS-Quality Model v1.0 WSQM – 5 family specifications

9. Business Value Business Value Quality Business Value Quality Quality Group Service Cost Effect Recognition level Suitability Effect Recognition level Service Measurement Service Level Measurement Quality Service Level Measurement Quality Quality Group Performance Stability Performance Stability System Information Business Processing Business Processing Quality Group Transaction Transaction Message Reliability Collaborability Message Reliability Collaborability Interoperability Interoperability Security Security Conformability Interoperability Conformability Interoperability Integrity Confidentiality Integrity Authentication Confidentiality Authentication Manageability Manageability Access Control Non - repudiation Accessibility Access Control Non - repudiation Accessibility Control Notification Control Introspection Notification Introspection Privacy Audit trail Privacy Audit trail WS-QF (Web Service Quality Factor) Business Value Business Value Quality Business Value Quality Quality Group Service Cost Service Suitability Service Aftereffect Service Brand Value Recognition level Recognition level Service Measurement Service Level Measurement Quality Service Level Measurement Quality Quality Group Performance Stability Performance Stability System Information Business Process Quality Business Processing Quality Group Transaction Transaction Message Reliability Collaboration Message Reliability Collaborability Suitability for Standards Interoperability Security Quality Security Conformability Interoperability Conformability Interoperability Integrity Confidentiality Integrity Authentication Confidentiality Authentication Manageability Quality Manageability Access Control Non-repudiation - Accessibility Access Control Non - repudiation Accessibility Management Information offerability Controlability Notification Control Notification Sing-Sign-On Privacy Privacy Audit Privacy Audit trail

10. WS-QF (Web Service Quality Factor) • Business Value Quality • Service Cost : a level of payment for value • Service Suitability : Is a particular service suitable for business operation? • Service Aftereffect : quantitatively or qualitatively expresses effect from a particular web service in business • Service Brand Value : collection of reputation shaped by users • Service Level Measurement Quality • Performance : response time to a service request • Stability : How stable web services provide services?

11. WS-QF (Web Service Quality Factor) • Suitability for Standards • Conformability : to evaluate if web services was built according to the standards • Interoperability : how well service information can be exchanged and used? • Business Process Quality • Message Reliability : to exchange without any errors • Transaction Process Ability : ability to process related tasks on process flow • Business Process Collaboration Ability : How well is the collaboration scheme with Web Services suitable to business process

12. WS-QF (Web Service Quality Factor) • Manageability Quality • Management information offerability • Observability : feature to provide the management information • Controlability : feature to change the inside information • Security quality • Confidentiality • Integrity • Authentication • Access control • Non-repudiation • Availability • Audit • Privacy • Sing-Sing on

13. Next Step • Applying WSQM in multiple sets of government guidelines, recommendations, and standards • Providing of quality information from WSQM test bed • Collaboration between national Web Services Registry

14. Consideration for Collaboration between EERP and WSQM

15. A table of contents • Core Technology of EERP • Consideration 1: Service granularity • Consideration 2: Weight for quality factor • Consideration 3: How to get quality Info. • Consideration 4: How to use quality info • Consideration 5: Common Service Quality • Consideration 6: Quality Chain

16. Core Technology of EERP • Quality of Service: Framework - QoS description, evaluation, audition, mapping.. • Dynamic Service Orchestration: Control - Resource optimization • eXtensible Web Service Description: Representation - extension of WSDL with QoS and semantic expressions of service functions • Granularity of Service: Composition - Search the optimized unit of services

17. Composite service Single or simple service Consideration 1: service granularity • WSQM focuses on quality factors of simple type service. EERP varies service granularity flexibly. • Considerations: Is WSQM proper model for various granularity of services? What part of WSQM or WSQDL should be changed for reflecting granularity?

18. Consideration 2: Weight for quality factor • Various quality factors for services. What is the major or minor factors for EERP selecting a service? • Each business requires different level of weight of quality factor for selecting a service. Now, WSQDL has no information of weight for quality factor. WSQDL 1 WSQDL 2 Service consumer 1 WSQDL 3 UDDI for quality info WSQDL n Service consumer 2

19. Consideration 3: How to get quality Info. • Getting time for quality information is different as quality factors. For completing WSQDL, it requires getting information carefully in each step and framework for collecting quality info. - Business related Info(cost, suitability,..): before running or after running - Operational related Info(measurement): while running - Technical related Info(Interop, security..): before running Suitable for Biz purpose? Yes Satisfy QoS in Tech? Yes Services for Biz Use the service No No Is it possible Wrapping or alternative? No use

20. Consideration 4: How to use quality info • EERP Dynamic service orchestration requires real-time service search with quality info. For the purpose, we use UDDI which has quality classification and updates it with the help of service quality management system. UDDI ② request new WS WS Quality Management System ③ provide WSDL of new WS ⑥ provide WS Quality Info ⑦ store the ref of WS Quality ⑤ Store Quality Info WS Quality Info ④ test with Agent ① WS registration WS connecting API WS Provider

21. WSQDL Metric Eval Biz Proc Biz Val Interop Sec Manage Secrecy Non-rep Consideration 4: How to use quality info • Each WS could be reclassified according to quality grade. • Because there are various quality factors, we need quality context for describing quality values. EERP system can find services more rapidly if WS is categorized in quality context. Quality context 1 value WSDL 1 Quality context 2 value Quality context 3 value Quality context 1 value WSDL 2 Quality context 2 value Quality context 3 value Quality context 1 value WSDL 3 Quality context 2 value Quality Management System Quality context 3 value UDDI

22. Consideration 5: Common Service Quality • In EERP, Some services could be packed for common service. In this case, users have more interest in service quality of packing unit more than each unit service. • If WSQDL support this type quality model, it makes quality system more simple. PS 2 PS 1 PS 3 Common Service Pack 1 Common Service Pack 2 WSQDL 1 WSQDL 2

23. Target Web services Measure factor Sub factor Metric Eval factor Property Sub property Function Performance Quality Factor Biz process factor Sub factor Property Function Performance Biz value factor Sub factor Property Appraisal Consideration 6: Quality Chain • The value of each quality factor is described in quality chain, in which each factor can refer the other factor. • Quality factor is composed of measure factor, evaluation factor, biz process factor, and biz value factor. • EERP can refer quality chain info for selecting a service

24. S2 S4 S5 S1 S3 Same purpose services eval/security/XML-enc Common value for quality factor keySize: 128 secAlgorithm: RSA Quality factor value in bandwidth encTime: 10ms-20ms Consideration 6: Quality Chain • If services are classified with business purpose and grouped in same quality context, we can find a service suitable for a situation. • Single value or value bandwidth for an item on quality chain is possible.

25. Thank You!! SoJung Kim (ksjnu@nia.or.kr)