The Workflow Management Coalition (WfMC) has released a draft beta version for the XML Process Definition Language (XPDL), together with a supporting XML schema. The document relates to WfMC's Interface One, supporting Process Definition Import and Export. The interface includes a common meta-model for describing the process definition and an XML schema specifying XPDL. Interface One is one of five functional interfaces to a workflow service identified by the WfMC as part of its standardization program. The draft document "describes the meta-model which is used to define the objects and attributes contained within a process definition. The XPDL grammar is directly related to these objects and attributes. This approach needs two operations to be provided by a vendor: (1) Import a workflow definition from XPDL; (2) Export a workflow definition from the vendor's internal representation to XPDL. The specification uses XML as the mechanism for process definition interchange. XPDL forms a common interchange standard that enables products to continue to support arbitrary internal representations of process definitions with an import/export function to map to/from the standard at the product boundary. A variety of different mechanisms may be used to transfer process definition data between systems according to the characteristics of the various business scenarios. In all cases the process definition must be expressed in a consistent form, which is derived from the common set of objects, relationships and attributes expressing its underlying concepts."

Bibliographic information: Workflow Process Definition Interface -- XML Process Definition Language. Workflow Standard. The Workflow Management Coalition Specification. From the Workflow Management Coalition. July 31, 2002. Document Number WFMC-TC-1025. Document Status: Draft 1.0 (Beta Status). Version 1.0 (Beta). 87 pages. See the accompanying XPDL XML schema.

From the XPDL (Beta) Introduction: "A variety of different tools may be used to analyse, model, describe and document a business process. The workflow process definition interface defines a common interchange format, which supports the transfer of workflow process definitions between separate products. The interface also defines a formal separation between the development and run-time environments, enabling a process definition, generated by one modelling tool, to be used as input to a number of different workflow run-time products. A workflow process definition, generated by a build-time tool, is capable of interpretation in different workflow runtime products. Process definitions transferred between these products or stored in a separate repository are accessible via that common interchange format. To provide a common method to access and describe workflow definitions, a workflow process definition meta-data model has been established. This meta-data model identifies commonly used entities within a process definition. A variety of attributes describe the characteristics of this limited set of entities. Based on this model, vendor specific tools can transfer models via a common exchange format. One of the key elements of the XPDL is its extensibility to handle information used by a variety of different tools. XPDL may never be capable of supporting all additional information requirements in all tools. Based upon a limited number of entities that describe a workflow process definition (the 'Minimum Meta Model'), the XPDL supports a number of differing approaches..."

Note that The Business Process Management Initiative (BPMI.org) and the Workflow Management Coalition (WfMC) in May 2002 announced a "formal joint meeting in London Wednesday June 26, 2002. The joint work would spotlight development of standards for Business Process Management and Workflow, with collaboration focusing on the use of BPMI.org's Business Process Modeling Language (BPML) for describing workflow processes, according to the workflow model defined by the WfMC... By projecting WfMC's workflow model onto BPML, companies [would] be able to develop end-to-end processes that include reliable back-end transactions and rich front-end user interfaces, in a standards-based manner..."

"The WfMC, founded in August 1993, is a non-profit, international organization of workflow vendors, users, analysts and university/research groups. The Coalition's mission is to promote and develop the use of workflow, in part through the establishment of standards for software terminology, interoperability and connectivity between workflow products. Consisting of over 300 members, spread throughout the world, the Coalition has become established as the primary standards body for this rapidly expanding software market. The Workflow Management Coalition has worked strenuously for the adoption of standards throughout the industry. Standards allow process definition and modeling tools to be used to specify the business process implemented by a different workflow engine, allow business processing systems to invoke and be invoked by workflow systems, and allow multiple workflow systems (within a single or multiple organizations) to operate together. They provide a fertile environment for workflow component development to grow and flourish, giving a rich array of options for user organizations."