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Copyright 2008, Workflow Management Coalition

BPEL &XPDL

Robert M. ShapiroChair, Process Interchange, WfMCSenior Vice President, ResearchGlobal 360

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Agenda

9:30-10:10 BPM 101

10:10-11:10 Architecture

11:30-12:30 XPDL and BPMN

12:30-1:00 Wf-XML1:45-2:15 Analytics

2:15-2:30 BPAF

2:30-3:00 BPEL3:00-3:30 Modeling

3:30-4:30 Open Discussion

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BPEL Proposed Standard

Web Service composition language

Used for web service orchestration

BPEL was originally developed by BEA,IBM, and Microsoft. Version 1.1 also

includes input from SAP and Siebel. The OASIS TC Web Services Business

Process Execution Language now

continues the standardization of BPEL

BPEL 2.0 Officially adopted in June 2007

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WS-BPEL Specifications History

BPEL4WS 1.0 (7/2002)

Original proposal from BEA, IBM, Microsoft Combined ideas from IBMs WSFL and Microsofts XLANG

BPEL4WS 1.1 (5/2003)

Revised proposal submitted to OASIS

With additional contributions from SAP and Siebel WS-BPEL 2.0 (6/2007)

Formalization of 1.1 capabilities

OASIS formally adopted standard

WS-BPEL 2.0 and beyond (10/2007) Additional proposals on the table

Vendors beginning to ship products conforming tostandards

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BPEL Design Goals*

Defines business processes that interact with

external entities through Web services The definitions use XML and are not concerned with

the graphical representation of processes

Defines a set of Web service orchestration concepts

Provides both hierarchical and graph-like controlregimes

Provides data manipulation functions sufficient formanipulation of data needed to define process

relevant data and control flow

*

Extracted from Goals of the BPEL4WS Specification by Leymann, Roller,and Thatte, working document submitted to OASIS August 25, 2003

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BPEL Design Goals*

Supports an identification mechanism for process

instances at the application message level Supports the implicit creation and termination of

process instances as the basic lifecycle mechanism

Defines a long-running transaction model to support

failure recovery Uses Web services as the model for process

decomposition and assembly

Builds on compatible Web services standards

*Extracted from Goals of the BPEL4WS Specification by Leymann, Roller,and Thatte, working document submitted to OASIS August 25, 2003

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WS-BPEL in the WS Stack

BPEL

XML, Encoding

Other protocols

Other services

Transportand

Encoding

BusinessProcesses

WSDL, Policy, UDDI, Inspection Description

SecurityReliable

Messaging

Transactions

Coordination

SOAP (Logical Messaging)

QualityOf

Service

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BPEL and WSDL

BPEL processes exposed as WSDL services

Message exchanges map to WSDL operations WSDL can be derived from partner definitions

and the role played by the process in interactionswith partners

Interfaces exposed by the BPEL process Interfaces consumed by the BPEL process

BPEL Data Model: Variables

Activities input and output kept in scopedvariables

Scoped variables typed as WSDL messages orXML Schema elements/types

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BPEL4People Extension Proposal

A major difference between XPDL and BPEL

Proposed by Adobe, BEA, IBM, Oracle and SAP Draft proposal (version 1.0) published June 2007

Currently soliciting suggestions and comments

Acknowledged need to incorporate people as a typeof participant, in additional to system centric tasks

It proposed defining a new type of basic activity(WSHumanTask) which uses human tasks as animplementation

Currently no roadmap timeline for this proposal tobe formally drafted as spec; work in progress

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BPEL vs.XPDL

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XPDL Enables Process Design Ecosystem

Vendor FVendor E

SOA DesignWorkflow Design

Vendor C Vendor DVendor BVendor A

Process Risk Mgmt Process Simulation

Process Execution

Process Modeling

Process ModelRepository

Process Optimization

Process Execution

Executable ModelRepository(e.g. XPDL)

Executable ModelRepository(e.g. BPEL)

Runtime Process Integration( Wf-XML )

X

ProcessDeploy

ment(typically

one-way)

Risk/ControlInformation

Ownership/IssueInformation

Resources/TimeInformation

Goals/Strategies

Tool- specificCapabilities

User Needs

Process

Structure isshared by alltools

Executionenvironments have

different strengths,no model exchangeat this level

PeopleIntegration

Limited Portability

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How BPEL and XPDL Relate to one another

BPEL is an executable language

Includes only executable operations Does not contain the graphical diagram

Many Engines have proprietary formats

They have a design tool

Even BPEL engines have proprietary extensions XPDL is a design interchange format that represents

the graphical diagram

Includes metadata about executable aspects

It is generally not possible to design a process witha tool from one vendor and execute it in anothervendors engine

But exchange between design tools is possible

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BPEL vs. XPDL (whats common)

Process definition standards

XML based

Built on process flows based on activities

Support inter-process messaging based on

WSDL Supported by customers, vendors,

consultants, academics and governments

Adopted by major BPM/ECM/EAI vendors Deployed in production

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BPEL vs. XPDL (whats different)

BPEL

Web services based processes System to system processes

No organizational based resources

No graphical information

No sub processes

BPEL 2.0 officially adopted in June 2007 XPDL

Designed for process model interchange

Includes organization based resources

Stores graphical information (compatible with BPMN)

Both web services and non web services based processes

Multiple processes in one package

XPDL 2.0 released October 2005 (XPDL 1.0 released2002)

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BPEL vs. XPDL (when should I use which)

BPEL

Great for web services based processes Great for system to system processes

Standard support by many BPM/EAI vendors

XPDL

Facilitates process interchange between designtools, simulators, BPA tools and execution engines

Models organization resources required by activities

Explicit support for BPMN graphical notation.Interchange format contains both process definitionsand graphical representation

Standard support by many BPM vendors

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Process Thought Leadership