1. 2006. 1. 2 Dugki Min Konkuk University
Web Services Quality Model
Dugki Min
Konkuk University

2. Related WS Specifications Future Work
Contents
Background
Motivation
Definition of Terms
WSQM
Quality Activity of WS
Quality Associates of WS
Quality Factors of WS
Related WS Specifications
Future Work

3. Background
Web Services become popular infrastructure for service-oriented integration
Business Web Services
Grid Web Services
Mobile Web Services
Ubiquitous Web Services
Web Services are valuable only if whose service qualities are satisfied by the consumers and guaranteed continuously.

4. Motivation
Everybody uses the term, WS Quality, and says it is important.
WSDM
UDDI
Service Contract
But, there is no clear-cut definition of what WS Quality is.
We need to have
Common Model of WS Quality
=> Web Service Quality Model
Common Language to describe WS Quality
=> Web Service Quality Description Language

5. Definition of Terms Quality Quality Model
: The totality of features and characteristics of a product or a service that bear on its ability to satisfy stated or implied needs. (ISO/IEC 9000)
Quality Model
: The set of quality-related actors, activities, characteristics of a product or a service and the relationship between them which provide the basis for specifying quality requirements and evaluating quality

6. Quality in Service-Level
WS Quality
Quality in Service-Level
In Use
In Management

7. Search, Negotiation, Contract, Implementation, Test, Deployment,…
WSQM
Quality Model
Search, Negotiation, Contract, Implementation, Test, Deployment,…
Quality Factors (Attributes)
Quality Associates
Quality Activity
Business Value Quality
Service Level Measurement Quality
Interoperability Quality
Business Processing Quality
Manageability Quality
Security Quality
Development Quality contract
Management Quality contract
Appropriation Quality contract
Service Stakeholder
Service Developer
Service Provider
Service Administrator (or operator)
Consumer
QoS Manager
QoS Broker (Assuror)
We composed WSQM with 3 components: QF, QA, and QA. QF represents the evaluating items for WSQ. Quality associates are the person or the organization related all the WS activities. Quality Activities represent the major operations for guaranteeing a level of WS between associates. The main activities are maybe contracting, monitoring, control, etc. Most of QF are provided as a form of independent specification. We will view and arrange these factors in the respect of qualities and focus the activities before normal execution or operating time. There could be many activities for preserving a level of WSQ such as Search, Negotiation, Contract, Implementation, Test, Deployment. We will specify these activities in the respect of relationship of associates and QFs.

8. Development Quality Contract
Quality Activity of WS
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
Service Developer
Service Development
Service stakeholder
Service
Operation &
Management
Service Provider
Service Broker
Service Quality
Contract
Management Quality
Contract
For example, let’s think about two quality activity.
Service Consumer
Quality Manager
Service user

9. Quality Associates for WS
Consumer & Provider
Stakeholder
Has a ownership of WS and requires WSQ to a developer
Uses WSQM in Quality Inspection Procedure
QoS Broker
Registers WS with quality properties and connect consumer and provider
Monitors whether registered WS keep a quality level
Quality Assuror
Guarantees WSQ by monitoring and controlling the quality level
Focus on Legal Assurance
3rd Party Quality Manager(3PQM)
Deputy manager of WS-provider
Monitors and manages system to secure required quality level from outside
Focus on Technical Management

10. Quality Associates for WS

11. Quality Factors (Attributes) of WS

12. Related WS Specifications
SLA Contract Standards
WSLA (IBM): Management by service level agreement
WS Management Standards
WSMF (HP): Layered Management Framework
WS-Manageability(IBM): Manageability Metamodel in type of Topic
WSDM 1.0 (OASIS): OASIS standard
MUWS: Composability + Manageability
MOWS: Manageability
Other related:
WS-Addressing: to find WS resources
WS-Notification: to notify change in resource state
We referred 2 main model. SLA provides management framework, In that management level is differentiated by service level contracted by service provider and consumer. WSMF provides well organized management framework: WSM, Foundation, Events.
WS-Manageability specifies well the manageability of metamodel in type of topic: Relationship, Identification, State, configuration, Metrics.
WSDM, approved as OASIS standard, provides two spec: MUWS and MOWS. MUWS is for managing any resources with WS.
So, it focus on the manageability and composability. The composability means that how easily WS management capability can be combined with resources. MOWS specify relationship model between manageability WS endpoint and manageable WS enpoint.

13. Future Work
Subject to WSQM TC