OASIS Service Component Architecture / BPEL (SCA-BPEL) Technical Committee

The original Call For Participation for this TC may be found at http://lists.oasis-open.org/archives/tc-announce/200707/msg00015.html

  1. Name

    OASIS Service Component Architecture / BPEL (SCA-BPEL) Technical Committee

  2. Statement of Purpose

    The SCA-BPEL TC will specify how SCA component implementations can be written using the WS-BPEL language[1]. The SCA WS-BPEL specification must allow any executable WS-BPEL 2.0 and BPEL4WS 1.1 process to be used without any knowledge of SCA. In addition, SCA specific extensions will be defined such that an executable WS-BPEL process may be aware of SCA and take advantage of that environment.

    This TC will continue development of the SCA for BPEL Client and Implementation Specification Version 1.0 [2] and aims to establish it as an OASIS Standard.

  3. Scope

    The SCA Assembly Model defines the environment in which SCA component implementations exist. The SCA WS-BPEL specification must conform to this environment and as a result, the following should be covered by the SCA WS-BPEL specification:

    1. Mapping of WS-BPEL PartnerLinks to SCA Services and References.

      This must take into account:

      1. the directionality of the roles in the PartnerLink
      2. the initializePartnerRole attribute
      3. whether a role is initialized through assignment before it is used
    2. Ensure correct behaviour of SCA call-backs and conversations. SCA extensions may be defined to support conversations for SCA aware WS-BPEL implementations.
    3. Ensure support for dynamic binding of partner links in SCA environment, especially the wire-by-impl feature.
    4. SCA extensions to WS-BPEL to support a PartnerLink that may have multiple partners of the same type. This should provide a simple mechanism to iterate over a number of partners of the same type as in an RFQ interaction, for example.
    5. SCA extensions to WS-BPEL to enable SCA properties to be used for initialization purposes.
    6. SCA extensions to WS-BPEL to enable other features defined in the SCA specifications to be explicitly used.

    The TC will accept as input the March 2007 Version 1.0 of the Service Component Architecture (SCA) BPEL Client and Implementation Specification as published by the Open SOA collaboration [2].

    The TC will also accept as input for reference the March 2007 Version 1.0 of the other SCA Specifications which were published at the same time as the SCA BPEL Client and Implementation Specification [3].

    Other contributions may be made by TC Members on or after the first meeting of the TC. Such other contributions shall be considered by the TC Members on an equal basis to improve the original starting point contribution in a manner that is compliant with this charter.

    Upwards Compatibility

    There are no formal requirements for upwards compatibility from the input documents to this TC. This is to ensure that the TC has maximum freedom of action in defining the OASIS standard. However it is recognized that there will be early implementations in the marketplace based upon these input documents and careful consideration must be applied to any change of feature/function that would cause incompatibilities in the OASIS standard at:

    • Source Code level
    • Compiled Object Code
    • XML data definitions

    At minimum, known enhancements to the input documents that will cause compatibility issues with early implementations in the marketplace will be specified in a chapter in the specification offering migration guidance.


    In line with the OASIS TC process, the TC will produce normative conformance information describing the normative characteristics of the specification and specific statements about what an implementation must do to conform to the specification, and what aspects are optional (if any).

    Test Suite

    The TC will produce a test suite which can be used to test conformance to the specification which will include:

    1. A series of valid and invalid test cases which cover as much as is practical of the conformance statements of the specifications produced by this TC, with a description of each of the artifacts involved, constraints on the environment, the test case characteristics and their expected behavior. The artifacts should include example WS-BPEL implementations used to drive the test cases.
    2. With the exception of necessary WS-BPEL implementation test artifacts, the provided artifacts should be independent of implementation language and binding type, and show clear mappings which allow the provision of suitable concrete implementations and concrete binding type, with any required policies. The artifacts may include SCA composites expressed in XML, WSDL interface files, and XSD files, along with other similar files that express the required characteristics of the environment for each test.
    3. Example bindings may form part of the test suite, and are only provided as working samples which can be replaced by other specific bindings.

    The Test Suite shall be packaged separately from the specifications produced by the TC and will contain a set of materials including but not limited to SCA composite and related SCA files, WS-BPEL files, WSDL files, XSD files.

    The TC shall develop the test suite in collaboration with other TCs within the Open-CSA Member Section.

    The following material should be considered as best practice for the preparation of conformance and test suite materials:

    Out of Scope

    The following are explicitly out of scope for the SCA-BPEL TC:

    1. Any changes to the WS-BPEL language as published by OASIS[1]
    2. Definitions of any new profiles of WS-BPEL
    3. Extensions to the WS-BPEL language that are not related to SCA, as directed by the SCA specifications model.
    4. Abstract WS-BPEL
    5. Additional workflow, orchestration and choreography languages and notation.
  4. Deliverables

    The TC has the following set of deliverables:

    • A revised SCA for BPEL Client and Implementation specification inclusive of XML Schema and other ancillary documents, together with a complete set of conformance statements
    • A complete Test Suite specification for the SCA for BPEL C+I Specification, including documents and the related materials described in the scope section.

    An approved Test Suite is scheduled for completion within 12 months of the first TC meeting.

    The TC may decide to change the names of the documents included in the starting point contribution, and the TC may decide to modularize into multiple documents.

    Exit Criteria

    The TC shall define concrete exit criteria that include at least two independent offerings that implement and are compliant with the all normative portions of specifications and demonstrate interoperability and portability as appropriate. Note that these are minimums and that the TC is free to set more stringent criteria.


    Once the TC has completed work on a deliverable and it has become an OASIS standard, the TC will enter "maintenance mode" for the deliverable.

    The purpose of maintenance mode is to provide minor revisions to previously adopted deliverables to clarify ambiguities, inconsistencies and obvious errors. Maintenance mode is not intended to enhance a deliverable or extend its functionality.

    The TC will collect issues raised against the deliverables and periodically process those issues. Issues that request or require new or enhanced functionality shall be marked as enhancement requests and set aside. Issues that result in the clarification or correction of the deliverables shall be processed. The TC shall maintain a list of these adopted clarifications and shall periodically create a new minor revision of the deliverables including these updates. Periodically, but at least once a year, the TC shall produce and vote upon a new minor revision of the deliverables.

  5. IPR Mode

    The TC will operate under the RF on Limited Terms mode under the OASIS IPR Policy.

  6. Anticipated audience

    The anticipated audience for the documents produced by this TC includes:

    • Software product vendors supporting Service Component Architecture and BPEL
    • Software developers, architects and other roles involved with design, development, deployment and maintenance of SCA components implemented in BPEL.
  7. Language

    The TC shall conduct its proceedings in English.


[1]WS-BPEL version 2.0, OASIS Standard, April 2007

[2]SCA BPEL Client and Implementation, V1.00, March 2007

[3]SCA Assembly Model, V1.00, March 2007

[4]Open SOA Collaboration