W3C Architecture Domain

Web Services Architecture Working Group Charter

  1. Scope of the Web Services Architecture Working Group
    1. Architecture document
      1. Out of Scope
    2. Role and relationship with other Working Groups
  2. Schedule
  3. Relationships with Other Work
    1. W3C Groups and Activities
    2. External Groups
  4. Participation, Meetings, and Logistics
    1. Participation
    2. Email Communication
    3. Group Home Page
    4. Meetings
    5. Resources
    6. W3C Team Involvement
    7. Intellectual Property

This charter is an updated version of the 2002-01-26 charter: it reflects the change of chairs which occurred on 22 July 2002. No other modification has been made.

1 Scope of the Web Services Architecture Working Group

The advent of XML makes it easier for systems in different environments to exchange information. The universality of XML makes it a very attractive way to communicate information between programs. Programmers can use different operating systems, programming languages, etc, and have their software communicate with each other in an interoperable manner. Moreover, XML, XML namespaces and XML schemas serve as useful tools for providing mechanisms to deal with structured extensibility in a distributed environment, especially when used in combination.

The same way programmatic interfaces have been been available since the early days of the World Wide Web via HTML forms, programs are now accessible by exchanging XML data through an interface, e.g. by using SOAP Version 1.2, the XML-based protocol produced by the XML Protocol Working Group. The services provided by those programs are called Web services.

The power of Web services, apart from their great interoperability and extensibility thanks to the use of XML, is that they can then be combined in order to achieve more complex operations.

In order to get a complete automation of such interactions, the architecture of Web services needs to be better understood, and several technologies need to be developed.

Several proposals have been published by different organizations to address different parts of the required task. The goal of the Web Services Architecture Working Group is to lay out a coherent architecture, by producing architectural documents and advising W3C regarding work in the Web services area.

The remainder of this section describes in detail the requirements and deliverables of Web Services Architecture Working Group, part of the Web Services Activity.

1.1 Architecture document

The area of Web services is broad. Many different functionalities are required in order to obtain a fully automated, functional, distributed system. The Working Group is tasked to come up with a document which will describe the architecture of Web Services.

The following goals are sought:

Keys to the success of Web services are privacy and security. The Working Group will assess how these need to be addressed.

The architecture document will identify the technologies necessary for Web services to be used, described, discovered, how Web services interact with each other (such as long-time conversations, routing, composition, ...), etc. The Working Group will use the conclusions reached during the Web services workshop as an input for this work. The Working Group should also identify what existing W3C technologies already address functions required by the architecture identified.

In particular, the Working Group will clearly delimit the boundaries of each identified component, and model the interfaces between them, so that the scope of new Working Groups created to address each piece of is unambiguously defined.

The Working Group will also provide a model of the various Web services concepts used in the various Working Groups in order to ensure that the various specifications actually work together and use the same concepts and terminology. The Working Group may also suggest a glossary used by Web Services specifications in order to ensure the consistency of Web Services terms.

The Working Group will also assess the relationship with the work conducted in the Semantic Web Activity.

The Working Group shall start by developing a requirements document detailing and refining the scope of its work.

1.1.1 Out of Scope

The Working Group will describe a detailed architecture. However, it is out of the scope of the Working Group to design the technologies suggested. The Working Group should describe those identified technologies by defining their scope.

Those descriptions will be used as input by the Web Service Coordination Group for the chartering of new Working Groups at a later date.

1.2 Role and relationship with other Working Groups

The W3C Web Services Activity is chartered with developing a set of technologies which will lead Web services to their full potential.

The architecture document produced by the Web Services Architecture Working Group will be of crucial importance to the future developments of the Web Services Activity.

Working Groups developing Web services technology must coordinate with the Web Services Architecture Working Group in order to keep a coherent overall architecture. This is why the high-level view developed by the Working Group will be influenced by work happening in other Working Groups, particularly the ones under the Web Services Activity.

Such coordination will take place in the Web Services Coordination Group; its task is to coordinate efforts in the Web Services Activity and other related groups. The Coordination Group will use the architecture document produced by the Web Services Architecture Group as a guide for its decisions.

Even though it is likely that some proposals made by independent parties are already trying to address some of the architecture that the Working Group will come up with, not all those areas will be ready for standardization at the same time.

The Web Services Architecture Working Group will be developing and maintaining a roadmap. Input gathered at the Coordination Group level will be used to provide such a deliverable.

2 Schedule

These are subject to revision due to editorial needs and external scheduling issues; updates will be negotiated with the related groups and recorded on the Web Services Architecture Working Group home page. Meeting dates are mentioned here for planning purposes.

January 2002
Activity start and Working Group formation.
March 2002
First Working Group face-to-face meeting.
April 2002
First requirements document for Web services architecture.
June 2002
First Working Draft of the Web services architecture document.
January 2003
Last Call Working Draft for the Web services architecture document.
March 2003
Proposed Recommendation for the Web services architecture document.
May 2003
Recommendation for the Web services architecture document.
January 2004
Working Group ends.

The expected duration of the Working Group is 2 years, through January 2004.

3 Relationship with Other Work

3.1 W3C Groups and Activities

XML and XML-derived activities have become a strategic technology in W3C and elsewhere. Each deliverable of any Working Group must satisfy the dependencies from other W3C Working Groups before it can advance to Candidate Recommendation.

Technical Architecture Group
The TAG is chartered to document and build consensus around principles of Web architecture and to interpret and clarify these principles when necessary. When necessary, the Web Services Architecture Working Group will refer issues to the Technical Architecture Group.
XML Activity
Web services make an extensive use of XML. While no dependencies are presently identified, the Web Services Architecture Working Group should be prepared to coordinate with the XML Activity as necessary.
Web Services Activity
Through the Web Services Coordination Group, the Working Group will make sure that the architecture described is in adequation with the work going on in the other Working Groups under the Web Services Activity. It is expected that other Working Groups will be formed to deal with different aspects of the Web services architecture. The Working Group will closely coordinate its work with any other Working Group formed within the Web Services Activity and generally in the Web services area.
Semantic Web Activity
The Semantic Web aims at transforming the Web into a completely machine-processable information space. Web services are aiming at enabling automated distributed computing on the World Wide Web. The Web Services Architecture Working Group will be interested in the approach used by Semantic Web applications, and the Semantic Web Activity should review the architecture laid out by the Working Group. The Working Group will participate in the Semantic Web Coordination Group.
XML Signature Activity
XML Signature will have an important role in communication identification.
XML Encryption Activity
XML Encryption is a technology which provides document-level security.
XML Key Management Activity
The XML Key Management Working Group's mission is to develop a specification of XML application/protocol that allows a simple client to obtain key information (values, certificates, management or trust data) from a Web service.
Platform for Privacy Preferences (P3P) Activity
Privacy will have an important impact in the use of Web services.
XForms Working Group
XForms can be seen as Web services providing a user interface. The Working Group will identify how Web services and XForms relate.

The Web Services Description Working Group will take the architecture document produced by the Web Services Architecture Working Group into account while developing its description language.

The Web Services Coordination Group, as well as new Working Groups formed under the Web Services Activity, will also pay particular attention to the documents produced by the Web Services Architecture Working Group.

3.2 External Groups

The Web Services Architecture Working Group should liaise with at least the following groups outside W3C:

ebXML Joint Co-ordination Committee
The ebXML initiative was a joint activity of UN/CEFACT (the United Nations body responsible for UN/EDIFACT) and OASIS (Organization for the Advancement of Structured Information Standards). Their charter was to develop an XML-based infrastructure for electronic commerce, with a particular focus on making connections between EDI and XML. While the original ebXML initiative's charter ended in May of 2001, the work transitioned to the respective sponsoring organizations (OASIS and UN/CEFACT) under the auspices of an MOU signed by the two in May of 2001.
During this current phase of ebXML, the initiative is managed through co-ordination between OASIS and UN/CEFACT in the form of the ebXML Joint Co-ordination Committee whose membership is made up of 3 representatives from OASIS board, 3 representatives from UN/CEFACT and technical representatives from each organization.
The Working Group will attempt to liaise with this committee.
Global Grid Forum
The Working Group will attempt to liaise with the Global Grid Forum. The Global Grid Forum is a community-initiated forum of individual researchers and practitioners working on distributed computing technologies.
The Object Management Group
OMG is a consortium that produces and maintains computer industry specifications for interoperable enterprise applications and which has experience in distributed, object-based systems. Remote operations have been standardized in the CORBA technology for many years. While there is a community need to perform remote operations using XML technology, and while some requirements may be new for electronic commerce, the development should not deviate in arbitrary ways existing standards such as UML, XMI, and MDA. The Working Group will attempt to liaise with OMG to ensure this.
DAML Services
The DAML Services arm of the DAML program is developing a DAML-based Web Service Ontology (currently named DAML-S), as well as supporting tools and agent technology to enable automation of services on the Semantic Web. DAML-S supplies Web service providers with a core set of markup language constructs for describing the properties and capabilities of their Web services in unambiguous, computer-interpretable form.

4 Participation, Meetings, and Logistics

4.1 Participation

To join the Web Services Architecture Working Group, please follow the instructions of section 4.2.3 of the Process Document, sending email to the Working Group Chair and the W3C Team contact. The nomination must include explicit agreement to this charter, including its goals, an IPR disclosure and the level of effort required of the representative.

Each Member organization may have at most two participants in the Working Group. Only Working Group participants may engage in formal votes on substantive issues. When a formal vote is required, each Member organization or group of related Members is allowed one vote, even though the Member may have several participants in the Working Group.

The W3C Team is expected to have at most two participants in the Working Group (including the Team contact). When a formal vote is required, the Team is allowed one vote.

Membership is also open to invited experts from the community, selected by the Chair in order to balance the technical experience of the group.

Each participant should expect to spend one day per week on work for this Working Group.

4.2 Email Communication

The Working Group will utilize a public mailing list <www-ws-arch@w3.org> for its technical email communications. It is referred to in the rest of this document as the Working Group mailing list.

A Member-only mailing list <w3c-ws-arch@w3.org> is available for administrative purposes only.

4.3 Group Home Page

The Working Group has a home page that records the history of the group, provides access to the archives, meeting minutes, updated schedule of deliverables, membership list, and relevant documents and resources. The page will be available to the public and will be maintained by the Chair in collaboration with the W3C team contact.

4.4 Meetings

The Working Group will have distributed and face-to-face meetings.

A one to two hour Working Group distributed meeting will be held every week. When necessary to meet agreed-upon deadlines, distributed meetings may be held twice a week.

The Working Group may schedule face-to-face meetings in a manner that maximizes co-location with events that Working Group members would be attending anyway.

Participation in meetings (distributed or face-to-face) is limited to participants in good standing and individuals invited at the discretion of the Chair to specific meetings.

Decisions taken in meetings must be announced on the Working Group mailing list. Observers may take part in decision-making at the discretion of the Chair.

Meeting records must include attendance, the results of group decisions, and action items. They must be made publicly available except for non-technical issues that do not directly affect the output of the Working Group. The Chair will decide which issues are not made public.

4.5 Resources

To be successful, we expect the Working Group to have approximately 10 to 15 active participants. A large public review group that will participate in the mailing list discussions is expected.

The Chair for the Web Services Architecture Working Group will be Christopher Ferris (Sun Microsystems).

Note: The new Chairs for the Web Services Architecture Working Group are Michael Champion (Software AG) and Dave Hollander (Contivo) effective 22 July 2002.

4.6 W3C Team Involvement

Initially, the Team will only have one participant in the Working Group, the Team contact. Hugo Haas will be full-time Team contact for both the Web Services Architecture Working Group and Web Services Coordination Group.

4.7 Intellectual Property

W3C promotes an open working environment. Whenever possible, technical decisions should be made unencumbered by intellectual property right (IPR) claims. W3C's policy for intellectual property is set out in section 2.2 of the W3C Process document.

Members of the Working Group are expected to disclose any intellectual property they have in the area. This WG will work on a royalty-free basis, as defined in the W3C Current Patent Practice document. The Working Group is thus obliged to produce a specification which relies only on intellectual property available on a royalty-free basis.

If it proves impossible to produce specifications implementable on a royalty-free basis, then a Patent Advisory Group will be launched as described in the W3C Current Patent Practice document.

Members disclose patent and other IPR claims by sending email to <patent-issues@w3.org>, an archived mailing list that is readable by Members and the W3C Team. Members must disclose all IPR claims to this mailing list but they may also copy other recipients. IPR disclosures are expected to be made public; Members should specify if their disclosure is confidential.

Chairs: Michael Champion and Dave Hollander
Team Contact: Hugo Haas
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