Business Process Execution Language BPEL

1
Business Process Execution Language (BPEL)

• Rich Powers
• CSC 9010 Service Oriented Architecture
• Spring 2008

2
Agenda

• Business Process 101
• Business Processes Automation Web Service
  Standards
• WS-BPEL Overview
• Intalio BPMS BPEL Platform
• Future Directions for WS-BPEL Adoption

3
Key Questions

• What is the concept of Business Process
  Automation and workflow technologies?
• What are the technologies and standards that
  constitute the SOA approach for Business Process
  Automation?
• What are the prospects for adoption of BPEL and
  the future direction of standards-based Business
  Process Automation leveraging web services?

4
Agenda

• Business Process 101
• Business Processes Automation Web Service
  Standards
• WS-BPEL Overview
• Intalio BPMS BPEL Platform
• Future Directions for WS-BPEL Adoption

5
Business Processes Defined

• A business process is a collection of
  interrelated tasks, which are designed to deliver
  a particular result
• Types of business processes
• Management processes - processes that govern the
  operation of a system
• Operational processes - processes that constitute
  the core activities of the business and delivers
  the primary value of the organization
• Supporting processes - which support the core
  processes
• A business process can be decomposed into several
  sub-processes, which have their own attributes,
  but are aligned with the goal of the overall
  process
• The analysis of business processes typically
  includes the mapping of processes and
  sub-processes down to an activity level
• Business processes can be automated through BPM
  software and workflow

6
Holy Grail of BPM

• IT becomes the enabler of business agility
  through the systemization of flexible processes
• However
• Business processes, by nature, are a challenge
  to identify, document, implement, and change

7
Business Process Automation

• Key Questions for Workflow Design
• Who Should?
• Who is involved in the process
• Do What?
• What tasks/activities need to be performed
• To What?
• What entities (objects) and data involved
• When?
• What starts and stops the process
• In What Order?
• What is the sequence and interrelationship
  between tasks
• Why?
• What is the value proposition of using workflow

8
Expected Benefit of Workflow Automation

• Improve the speed of a business process
• Improve the consistency of a business process
• Improve the quality of a business process
• The key challenge in workflow automation is to
  determine the ROI and business value to be
  achieved through the introduction of technology

9
Workflow Patterns(www.workflowpatterns.com)

• Basic Control Flow
• Sequence
• Parallel Split
• Synchronization
• Exclusive Choice
• Advanced Branching and Synchronization
• Multi-Choice
• Structured Synchronizing Merge
• Multi-Merge
• Structured Discriminator
• Blocking Discriminator
• Multiple Instance Patterns
• Multiple Instances without Synchronization
• Multiple Instances with a Priori Design-Time
  Knowledge
• Multiple Instances with a Priori Run-Time
  Knowledge
• State-Based Patterns
• Deferred Choice
• Interleaved Parallel Routing
• Milestone

• Cancellation and Force Completion Patterns
• Cancel Task
• Cancel Case
• Interation Patterns
• Arbitrary Cycles
• Structured Loop
• Recursion
• Termination Patterns
• Implicit Termination
• Explicit Termination
• Trigger Patterns
• Transient Trigger
• Persistent Trigger

10
Agenda

• Business Process 101
• Business Processes Automation Web Service
  Standards
• WS-BPEL Overview
• Intalio BPMS BPEL Platform
• Future Directions for WS-BPEL Adoption

11
Web Services Standards for SOAThe Web Services
Platform Architecture
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Web Services Standards for SOAThe Web Services
Platform Architecture
WS-C WS-N
WS-RF
WS-BPEL
SCA
UDDI, WS-Addr, Metadata Exch.,
WS-RM
WS-Security
WS-AT WS-BA
WSDL
WS-Policy
SOAP, WS-Addr
JMS, RMI/IIOP, ...
HTTP, TCP/IP, SMTP, FTP,
13
Web Services Standards for SOAThe Web Services
Platform Architecture
WS-C WS-N
WS-RF
WS-BPEL
SCA
UDDI, WS-Addr, Metadata Exch.,
WS-RM
WS-Security
WS-AT WS-BA
WSDL
WS-Policy
SOAP, WS-Addr
JMS, RMI/IIOP, ...
HTTP, TCP/IP, SMTP, FTP,
14
Agenda

• Business Process 101
• Business Processes Automation Web Service
  Standards
• WS-BPEL Overview
• Intalio BPMS BPEL Platform
• Future Directions for WS-BPEL Adoption

15
Business Process Execution Language (BPEL)

• Web Services Business Process Execution Language
  (WS-BPEL) is a language for describing business
  processes based on Web Services
• Processes described using WS-BPEL execute
  functionality by using Web Service interfaces
  exclusively
• WS-BPEL Specification is administered by OASIS
• WS-BPEL is an orchestration language, not a
  choreography language
• Orchestration specifies an executable process
  that involves message exchanges with other
  systems, such that that the message exchange
  sequences are controlled by the orchestration
  designer.
• Choreography specifies a protocol for
  peer-to-peer interactions, defining the legal
  sequences of messages exchanged with the
  objective of guaranteeing interoperability
• A choreography is not directly executable
• A choreography can be implemented through an
  orchestration (i.e. a BPEL process)

16
BPEL Standard Sponsorship
17
WS-BPEL 2.0 History

• Dec 2000
• Microsoft publishes XLANG
• March 2001
• IBM publishes WSFL
• July 2002
• IBM, Microsoft, BEA converge WSFL and XLANG into
  BPEL4WS 1.0
• March 2003
• BPEL4WS is submitted to OASIS
• May 2003
• OASIS publishes BPEL4WS 1.1
• April 2007
• WS-BPEL 2.0 standard

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WS-BPEL Design Goals

• Business processes defined using an XML-based
  language
• Web services are the model for process
  decomposition and assembly
• The same orchestration concepts are used for both
  the external (abstract) and internal (executable)
  views of a business process
• Both hierarchical and graph-like control regimes
  are used, reducing the fragmentation of the
  process modeling space
• An identification mechanism for process instances
  is provided at the application message level
• The basic lifecycle mechanism is in implicit
  creation and termination of process instances.
• A long-running transaction model is defined to
  support failure recovery for parts of
  long-running business processes
• Language built on compatible Web services
  standards in a composable and modular manner

19
WS-BPEL Language Constructs

• WS-BPEL process definition
• Recursive composition and partner links
• Variables
• Correlation sets
• Basic and structured activities
• Scopes
• Compensation handling

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WS-BPEL Process Definition
process
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Recursive Composition Model
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Partner Links Element

• WDSL describes functionality of services provided
  by a partner
• Partner Link describes the shape of the
  relationship with a partner by describing the
  Port Types used in a peer to peer relationship
• Example
• ltpartnerLinksgt
• ltpartnerLink nameInvoice
• partnerLinkTypeinvInvoiceType
• partnerRoleInvoiceServiceProvider/gt
• ltpartnerLink nameEmployee
• partnerLinkTypeempEmployeeType
• partnerRoleEmployeeServiceProvider/gt
• lt/partnerLinksgt

Reference to WDSL portType element
23
Partner Links
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Variable Element

• Variable construct is used to state information
  related to workflow logic
• Variables can contain entire messages and data
  sets formatted as XSD schema types
• Example
• ltvariablesgt
• ltvariable nameEmployeeHoursRequest
• messageTypeempgetWeeklyHoursRequestMessage/gt
• lt/variablesgt

Message Name from Partner Process Definition
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Variables
process
xsltransform
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Properties and Correlation Sets

• How to identify stateful instances via stateless
  WS interfaces?
• A process instance is assigned one or more keys
• Business data is used as key, e.g., customerID
• A key can be compound, e.g., (customerID,
  orderNumber)
• WS-BPEL calls a key a correlation set it is
  used to correlate an incoming message with a
  process instance

Process 4(0123,15)
Process 3(0815,42)
Process 2(4711,37)
Process 1(0815,12)
27
Basic Activities
process
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Structured Activities
process


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Scopes
process
Scopes provide a context which influences the
execution behavior of its enclosed activities
Isolated scopes provide control of concurrent
access to shared resources
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Compensation Handling
6. Undo work (in reverse order)
1. Do some work (successfully invoke two services)
2. Invoke another service (throws fault)
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BPEL Syntax ExamplePartner Definition

• lt?xml version"1.0" encoding"utf-8"?gt 
• ltprocess name"insuranceSelectionProcess"
• targetNamespace"http//packtpub.com/bpel
  /example/"
• xmlns"http//schemas.xmlsoap.org/ws/2003
  /03/business-process/"
• xmlnsins"http//packtpub.com/bpel/insur
  ance/"
• xmlnscom"http//packtpub.com/bpel/compa
  ny/" gt
•  
• ltpartnerLinksgt
• ltpartnerLink name"client"
• partnerLinkType"comselectionL
  T"
• myRole"insuranceSelectionServi
  ce"/gt
•  
• ltpartnerLink name"insuranceA"
• partnerLinkType"insinsuranceL
  T"
• myRole"insuranceRequester"
• partnerRole"insuranceService"/
  gt
•  
• ltpartnerLink name"insuranceB"
• partnerLinkType"insinsuranceL
  T"

32
BPEL Syntax Example Variable Definition

• ltvariablesgt
• lt!-- input for BPEL process --gt
• ltvariable name"InsuranceRequest"
• messageType"insInsuranceRequestM
  essage"/gt
• lt!-- output from insurance A --gt
• ltvariable name"InsuranceAResposne"
• messageType"insInsuranceResponse
  Message"/gt
• lt!-- output from insurance B --gt
• ltvariable name"InsuranceBResposne"
• messageType"insInsuranceResponse
  Message"/gt
• lt!-- output from BPEL process --gt
• ltvariable name"InsuranceSelectionResponse"
• messageType"insInsuranceResponse
  Message"/gt
• lt/variablesgt
• ...

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BPEL Syntax ExampleProcess Steps

• ltsequencegt
• lt!-- Receive the initial request from
  client --gt
• ltreceive partnerLink"client"
• portType"comInsuranceSelectionPT"
  
• operation"SelectInsurance"
• variable"InsuranceRequest"
• createInstance"yes" /gt
• lt!-- Make concurrent invocations to
  Insurance A and B --gt
• ltflowgt
•  
• lt!-- Invoke Insurance A web service --gt
• ltinvoke partnerLink"insuranceA"
• portType"insComputeInsurancePre
  miumPT"
• operation"ComputeInsurancePremiu
  m"
• inputVariable"InsuranceRequest"
• outputVariable"InsuranceAResposn
  e" /gt
•  
• lt!-- Invoke Insurance B web service --gt
• ltinvoke partnerLink"insuranceB"

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BPEL Syntax ExampleProcess Steps (Cont)

• lt!-- Select the best offer and construct the
  response --gt
• ltswitchgt
• ltcase condition"bpwsgetVariableData('Ins
  uranceAResposne',
• 'confirmationData','/conf
  irmationData/Amount')
• lt bpwsgetVariableData('Ins
  uranceBResposne',
• 'confirmationData','/conf
  irmationData/Amount')"gt
• lt!-- Select Insurance A --gt
• ltassigngt
• ltcopygt
• ltfrom variable"InsuranceAResposne"
  /gt
• ltto variable"InsuranceSelectionRes
  ponse" /gt
• lt/copygt
• lt/assigngt
• lt/casegt
• ltotherwisegt
• lt!-- Select Insurance B --gt
• ltassigngt
• ltcopygt
• ltfrom variable"InsuranceBResposne"
  /gt

35
Agenda

• Business Process 101
• Business Processes Automation Web Service
  Standards
• WS-BPEL Overview
• Intalio BPMS BPEL Platform
• Future Directions for WS-BPEL Adoption

36
Intalio BPMS Overview

• Intalio released a BPMS platform community
  edition under the Mozilla Public License (MPL) in
  late 2006
• Lighter version of Enterprise BPMS platform
• BPEL platform based on Apache Geronimo
  application server
• Graphical developer tool based on Business
  Process Modeling Notation (BPMN)
• Web site for code, documentation, and tutorials
  http//bpms.intalio.com

37
Agenda

• Business Process 101
• Business Processes Automation Web Service
  Standards
• WS-BPEL Overview
• BPEL Demonstration using Intalio BPMS
• Intalio BPMS BPEL Platform

38
WS-BPEL Adoption Products

• Active Endpoints ActiveBPEL
• BEA WebLogic
• Cape Clear Orchestrator
• Intalio/Apache Orchestration Director Engine
  (Ode)
• IBM WebSphere Process Server
• Microsoft BizTalk Server
• MidOffice BPEL Engine (open source)
• OpenLink Virtuoso Universal Server
• Oracle BPEL Process Manager
• Parasoft BPEL Maestro
• Progress Sonic BPEL Server
• SAP NetWeaver
• Sun eInsight BPM

39
WS-BPEL Follow-on Work

• BPEL4People human interactions
• http//www-128.ibm.com/developerworks/webservices/
  library/specification/ws-bpel4people/
• BPEL-SPE subprocess coordination protocol
• http//www-128.ibm.com/developerworks/webservices/
  library/specification/ws-bpelsubproc/
• BPELJ inline Java code in activities and
  expressions
• http//www-128.ibm.com/developerworks/library/spec
  ification/ws-bpelj/
• Currency with related standards
• WSDL 2.0, XPath 2.0, XQuery, etc.

40
WS-BPEL Standards Roadmap
WS-BPEL 2.0
www.oasis.org
WS-BPEL 2.0 Extensions for People
(BPEL4People) http//www-128.ibm.com/developerwork
s/webservices/library/specification/ws-bpel4people
WS-BPEL 2.0 Extensions for Sub-Processes
(BPEL-SPE) http//www-128.ibm.com/developerworks/w
ebservices/library/specification/ws-bpelsubproc W
S-BPEL 2.0 Extensions for Java (BPELJ) http//
Service Component Architecture (SCA) SCA Assembly
ModelSCA WS-BPEL Client and Implementation Model
ww.osoa.org
41
BPEL4People WS-HumanTask

• Specifications published June 25, 2007
• http//www-128.ibm.com/developerworks/webservices/
  library/specification/ws-bpel4people/
• Next step OASIS Technical Committee to be
  created to standardize BPEL4People and
  WS-HumanTask

42
BPEL4People WS-HumanTask Requirements

• Integration of human-executed activities in Web
  services-based business processes
• Integration of human-executed activities in
  SOA-based applications
• Standard-based solution to support
  interoperability and portability scenarios

43
BPEL4People WS-HumanTask Approach

• BPEL4People
• Definition of human interactions within WS-BPEL
  processes
• Specification built on top of WS-BPEL 2.0
• WS-HumanTask
• Definition of service-enabled human tasks and
  notifications
• Coordination protocol used to control autonomy
  and life cycle of service-enabled human tasks in
  an interoperable manner
• Interoperable programming interface enabling task
  client applications to work with human tasks

44
Service Component Architecture and WS-BPEL
Complementary Technologies

• Similarities between SCA and WS-BPEL
• Both are described in a formal language that is
  based on XML
• Both languages may be used to describe a business
  service that is implemented by composing together
  other business services
• Both can describe inbound and outbound service
  interactions types by WSDL port types
• SCA describes the structure of an application
• Components within the business application
• Services offered by components Service
  references components depend on
• Connections between components
• Endpoint addresses and communication methods used
  for the connections
• Policies applied to components and to the
  connections between them
• WS-BPEL describes the logic of a business process
• Sequences of operations which are performed to
  execute an individual business process
• Services provided and consumed through
  partnerLinks, that is, abstract interfaces that
  must be connected to actual endpoints and
  communication methods through configuration

45
BPEL Adoption within SOA

• Though it is one of the first web service
  standards published, the mainstream adoption of
  WS-BPEL has been slow
• BPEL specification was never a complete
  programming language
• The implementation of web service solutions have
  focused on HST and JBOWS patterns
• Gaps in functionality have been filled through
  the use of other programming tools and vendor
  specific extensions
• Cross version and cross platform interoperability
  has been problematic to date
• WS-BPEL 2.0 standard specification provides
  promise for improvements in terms of
  interoperability and functionality, however
  challenges remain
• WS-HumanTask and BPEL4People highlight the need
  to add additional semantics to BPEL
• Significant presence of well-established and
  highly capable legacy workflow products on the
  market
• Critical mass of web-services to orchestrate are
  still in development
• No standard graphical notation for WS-BPEL as the
  OASIS standards committee deemed it out of scope
• The question of how to create direct visual
  representation of BPEL process descriptions
  still needs to be addressed - Vendor Specific
  Notations, Business Process Modeling Notation
• BPMN to BPEL 2.0 modeling tools

46
BPEL Process Integration Scenario Microsoft - SAP

• SAP focused on formal business process workflows
  while Microsoft is focused on informal document
  workflows
• SAP application platform implementation deployed
  on Netweaver 7.0
• Implementation of business process automation
  using SAP PI which supports BPEL 2.0
• Microsoft collaboration implementation built on
  Sharepoint 2007
• Supports Microsoft WF as work flow engine
• Biztalk 2006 ? Netweaver PI to provide cross
  platform interoperability using BPEL 2.0