3146Modeling BPEL4WS

Richard C. GronbackSr. Product Manager, Together Products

Borland Software Corporation

Agenda

Introduction to BPM

BPEL4WS

Modeling BPEL4WS– BPMN– UML– BPMD

Deployment

Conclusion

What is BPM?

Business Process [Management | Modeling]• In general, the design, execution, maintenance,

and optimization of business processes.• Why model a business process?

– The same reasons we model software, or anything, really.

Remember, software development is a business process!

Available Notations & Methodologies

• UML Activity Diagram

• UML EDOC Business Processes

• IDEF

• ebXML BPSS

• Activity-Decision Flow (ADF) Diagram

• RosettaNet

• LOVeM

• Event-Process Chains (EPCs)

• Many more…

• There are literally hundreds of tools with varying capabilities, utilizing many disparate processes and notations.

BPMI.org

Business Process Management Initiative• Non-profit organization that aims to

establish standards for BPM• Working on specifications for:

– Business Process Modeling Language (BPML)– Business Process Modeling Notation (BPMN)– Business Process Query Language (BPQL)

• Focuses on private, internal implementation while ebXML, RosettaNet, etc. focus on external interfaces.

Orchestration vs. Choreography

Business Process

Business

Process B

Business

Process A

1. Message A

2.

3.

Message B

Message CChoreography

Orchestration

Message A

Message B BPEL4WS

ebXMLWS Choreography

BPEL4WS

• Business Process Execution Language for Web Services– Combination of IBM’s WSFL and

Microsoft’s XLANG– Specification authored by:

• IBM

• Microsoft

• BEA

• SAP

• Siebel Systems

BPEL4WS

• Defines a model and grammar for describing the behavior of a business process based on interactions between the process and its partners.– Exclusively using Web Services– Models executable and abstract processes– Layered on top of:

• WSDL 1.1• XML Schema 1.0• XPath 1.0

BPEL4WS Core Concepts

There are several core concepts of BPEL:• Partner Links• Variables• Correlation Sets• Fault Handlers• Activities

Structure of a BPEL “Program”State

InteractionPoints

Behavior

<variables> <variable name="PO" messageType="lns:POMessage"/> …</variables>

<partnerLinks> <partnerLink name="purchasing“ partnerLinkType="lns:purchasingLT" myRole="purchaseService"/> …</partnerLinks>

<sequence> <assign> <copy> <from variable="PO" part="customerInfo"/> <to variable="shippingRequest“ part="customerInfo"/> </copy> </assign> …</sequence>

BPEL4WS Usage Patterns

• Two major usage patterns, each specified by extensions to the core concepts:– Business Protocols

• Roles defined using notion of abstract process

• Handle only protocol-relevant dataIdentified as message properties

– Executable Processes• Logic and state determine nature and

sequence of Web Service interactions

How to Model BPEL4WS?

• BPEL4WS specification provides no visual notation well, except for what’s here

– Several possibilities:• Business Process Modeling Notation

(BPMN)• Unified Modeling Language (UML)• Proprietary visual notation based directly

on BPEL4WS

Why Model BPEL4WS?

• Consider this pseudo code for a simple Shipping Service:

receive shipOrder switch case shipComplete send shipNotice otherwise itemsShipped := 0 while itemsShipped < itemsTotal itemsCount := opaque // non-deterministic assignment // corresponding e.g. to // internal interaction with // back-end system send shipNotice itemsShipped = itemsShipped + itemsCount

Why Model BPEL4WS?

• Now, consider the following BPEL4WS process…

Why Model BPEL4WS?

Why Model BPEL4WS?

Why Model BPEL4WS?

Why Model BPEL4WS?

BPMN

Business Process Modeling Notation• Aims to appeal to wide range of users:

– Business Analysts– Developers– Business People

• 1.0 specification released May 2004• Defines elements of BPD (Business

Process Diagram)

Business Process Diagrams

Diagrams consist of four categories of diagramming elements:

– Flow Objects

– Connecting Objects

– Swimlanes

– Artifacts

BPD Flow Objects

Diagrams consist of three core elements:

– Event• Hollow to allow for markers

– Activity• Generic “work” element

– Gateway• Decision, forking, joining, merging

Start Intermediate End

Task Sub-Process

BPD Connecting Objects

Three ways to connect flow objects:• Sequence Flow

– Indicates order of activities

• Message Flow– Indicates flow of messages between Process

Participants

• Association– Associates data, text, or other Artifacts with flow

objects

Simple Business Process

BPD Swimlanes

Used to organize activities by responsibility or functional capability

• Pool– Represents a Participant

in a Process

• Lane– A sub-partition within a

Pool used to organize and categorize activities

BPD Artifacts

Any number of Artifacts can be added to a diagram, with three types predefined:

• Data Object– Show how data is required or produced by

activities

• Group– Used for documentation or analysis, but does

not affect the sequence flow

• Annotation– Allow for textual notes to be added

Another BPD Sample

Mapping BPMNBPEL4WS

• BPMN specification provides a mapping to BPEL4WS– Creates a bridge between business-

oriented process model to deployable execution language

– BPEL4WS XSD becomes a partial BPMN metamodel

Mapping BPMNBPEL4WS

• There are 3 basic types of BPMN sub-models:– Private (internal) business processes

• Maps to BPEL4WS process

– Abstract (public) processes• Maps to BPEL4WS abstract process

– Collaboration (global) processes• Someday, may map to ebXML BPSS, RosettaNet,

or future W3C Choreography Working Group

BPMN Private Process

Example:

BPMN Abstract Process

Example:

BPMN Collaboration Process

Example:

Unified Modeling Language™

• The UML 2.0 metamodel is adequate for modeling business processes

• A Profile applied to existing specification can allow for modeling BPEL4WS

• Optionally, a constrained subset of the UML 2.0 metamodel can also be used– Business Process Metamodel

Definition (BPDM)

BPDM

Business Process Definition Metamodel• Subset of UML 2 metamodel focused on

modeling business processes• Revised 08/02/2004 submission by:

– IBM– Adaptive– Borland– Data Access Technologies– EDS– 88 Solutions

BPDM

Contains the following:– UML 2.0 Profile for BPD– UML 1.5 Profile for BPEL4WS– Mapping from BPD Metamodel to BPEL4WS– Mapping from EDOC to BPD Metamodel– Mapping from BPMN to BPD Metamodel

BPDM

BPDM Notation

Services and Processes

BPDM Notation

Tasks

BPDM Notation

Tasks

BPDM Notation

Pins and Flows

BPDM Notation

Pins and Flows

BPDM Notation

Miscellaneous

BPDM Example

BPDM Example

BPDM Example

Mapping to BPEL4WS

From BPMN

BPMNBPEL4WS Example

BPMNBPEL4WS Loop

BPMNBPEL4WS Loop

Mapping Example

• Let’s explore the diagram elements and mappings of BPMN to BPEL4WS– Domain is E-mail Voting Process

• From BPMN Specification• Focus here is on Discussion Cycle sub-

process for simplicity

E-mail Voting Process

Mapping Discussion Cycle

• Discussion Cycle sub-process in BPD (of BPMN) maps to BPEL4WS process– Invocation from higher-level process means it

will start with receive and end with reply

<process name="Discussion_Cycle"> <sequence> <receive partnerLink="Internal" portType="tns:processPort"

operation="call_Discussion_Cycle" variable="processData" createInstance="Yes"/>

. . . <reply partnerLink="Internal" portType="tns:processPort" operation="call_Discussion_Cycle" variable="processData"/> </sequence></process>

Discussion Cycle

Announce Issues

• The “Announce Issues for Discussion” task maps to a BPEL4WS invoke

<invoke name="AnnounceIssuesforDiscussion" partnerLink="WGVoter" portType="tns:emailPort" operation="sendDiscussionAnnouncement" inputVariable="processData"/>

Discussion Cycle

Parallel Paths

• The output of the “Announce Issues for Discussion” task follows 3 paths that map to a BPEL4WS flow element

<flow><invoke name="ModerateEmailDiscussion" …… <invoke name="EMailDiscussionDeadlineWarning" ……<invoke name="CheckCalendarforConferenceCall" ……

</flow>

Discussion Cycle

Upper Parallel Path

• The Moderate E-mail Discussion task maps to a synchronous BPEL4WS invoke element

<invoke name="ModerateEmailDiscussion" partnerLink="internal" portType="tns:internalPort“ operation="sendDiscussion“ inputVariable="processData“ outputVariable="processData"/>

Upper Parallel Path

• The Timer Intermediate Event on task boundary maps to scope element wrapping the invoke element with faultHandlers

<scope><invoke name="ModerateEmailDiscussion" …<faultHandlers>

<catch faultName="7Days_Exit"><empty/>

</catch></faultHandlers>

…

Upper Parallel Path

• To create event at proper time, BPEL4WS eventHandlers added to the scope– Why the onAlarm to throw to empty

catch?… <eventHandlers>

<onAlarm for="tns:OneWeek"> <throw faultName="7Days_Exit"/></onAlarm>

</eventHandlers></scope>

Discussion Cycle

Middle Parallel Path

• The delay and E-Mail Discussion Deadline Warning task map to BPEL4WS wait and invoke elements within a sequence element.

<sequence> <wait name="Delay6daysfromDiscussionAnnouncement" for="P6D"/> <invoke name="EMailDiscussionDeadlineWarning" partnerLink="WGVoter" portType="tns:emailPort" operation="sendDiscussionWarning" inputVariable="processData"> </invoke></sequence>

Discussion Cycle

Lower Parallel Path

• The Check Calendar for Conference Call task maps to BPEL4WS invoke element.– A decision on output can be handled with a

BPEL4WS switch or reference links elements

<invoke name="CheckCalendarforConferenceCall" partnerLink="internal" portType="tns:internalPort" operation="receiveCallSchedule" inputVariable="processData" outputVariable="processData"> …</invoke>

Lower Parallel Path

• In this case, decision maps to BPEL4WS links in source elements with corresponding transitionCondition attribute.

<flow> <links> <link name="CheckCalendarforConferenceCalltoWaituntilThursday,9am"/> <link name="CheckCalendarforConferenceCalltoEmpty"/> …

<invoke name="CheckCalendarforConferenceCall" … <source linkName="CheckCalendarforConferenceCalltoWaituntilThursday9am" transitionCondition="bpws:getVariableProperty(processData,conCall)=true"/> <source linkName="CheckCalendarforConferenceCalltoEmpty" transitionCondition="not(bpws:getVariableProperty(processData,conCall)=true)"/> </invoke>

Lower Parallel Path

• From the “Yes” output from the decision, a BPEL4WS wait element is mapped.– The wait element contains nested target and

source elements with linkName attributes<flow> <links> … <link name="WaituntilThursday9amtoModerateConferenceCallDiscussion"/> <link name="CheckCalendarforConferenceCalltoWaituntilThursday,9am"/>… <wait name="WaituntilThursday9am" for="P6DT9H"> <target linkName="CheckCalendarforConferenceCalltoWaituntilThursday9am"> <source linkName="WaituntilThursday9amtoModerateConferenceCallDiscussion"/> </wait>

Lower Parallel Path

• Following the wait, the Moderate Conference Call Discussion task maps to a BPEL4WS invoke element.

<invoke name="ModerateConferenceCallDiscussion" partnerLink="internal" portType="tns:internalPort" operation="sendConCall" inputVariable="processData" outputVariable="processData"> <target linkName="WaituntilThursday9amtoModerateConferenceCallDiscussion"/></invoke>

Lower Parallel Path

• The default “No” output from the decision maps to a BPEL4WS empty element.– A merging Exclusive Gateway used to form

the end of lower parallel path before Parallel Gateway marks end of the flow

<empty> <target linkName="CheckCalendarforConferenceCalltoEmpty"/></empty>

Discussion Cycle

End of Parallel Paths

• Parallel Gateway marks end of flow and is followed by a task Evaluate Discussion Progress, which maps to BPEL4WS invoke element.– This marks end of outer sequence and the

process itself.… </flow> <invoke name="EvaluateDiscussionProgress" partnerLink="internal" portType="tns:internalPort" operation="receiveDiscussionStatus" inputVariable="processData" outputVariable="processData"/> <reply partnerLink="Internal" portType="tns:processPort" operation="call_Discussion_Cycle" variable="processData"/> </sequence></process>

Trouble Ticket Example

• Another example of notational differences– Comes from BPDM Examples to

compare:• BPDM• BPMN• UML2

BPDM Example

BPMN Example

UML2.0 Example

Model-Driven Architecture®

How does modeling BPEL4WS relate

to MDA®?

• According to the Object Management Group (OMG):– MDA provides an open, vendor-neutral approach to

the challenge of business and technology change.– MDA aims to separate business or application logic

from underlying platform technology.– Platform-independent models can enable intellectual

property to move away from technology-specific code, helping to insulate business applications from technology evolution, and further enable interoperability.

What is MDA?

The Benefits of MDA

Portability– Insulation from underlying technology change– Future-proof applications with domain model

Productivity– Code generation– Communicate visually, thereby reducing complexity

Cross-Platform Interoperability– Generated bridges

Easier Maintenance and Documentation– Design artifacts become development artifacts

• MDA is not a single specification, but a collection of related OMG specifications:– Unified Modeling Language (UML™) 2.0

• Infrastructure• Superstructure• Object Constraint Language (OCL)• Diagram Interchange• Profiles

– Meta-Object Facility (MOF)– XML Meta-Data Interchange (XMI)– Common Warehouse Meta-model (CWM)– Query View Transformation (QVT)

What Comprises MDA?

• Note the industry verticals… MDA is not intended to be a general purpose model-to-code solution.– Anticipate Domain-Specific Languages & Frameworks

The MDA Logo

Transformations

This is the challenge for MDA!• Inspired by existing CWM transformation technology

– MOF2 Core will align basis of UML and CWM• Query, View, Transformation specification is needed

– At present, QVT is MIA

A record of transformation is required to maintain traceability and synchronization.

Model Marking Transformation

Marks are specific to a transformation– Can be a stereotype in a profile, for example

Machine Code

Impossible?

The Abstraction Gap

Level of Abstraction

Generators

1

0..*

security

mortgages

1

0..*

borrower

mortgages

10..*

ownerhouses

House

-value:Money

Person

-ssn:Integer-salary:Money

+getMortgage(sum:Money,security:House):Mortgage

Mortgage

-principal:Money-monthlyPayment:Money-start:Date-end:Date

Machine Code with Operating System

Impractical?3GL with Operating System

Unlikely?3GL with Middleware

Practical(ly)Middleware with Framework

Today!

A b

s t r

a c

t i o

n G

a p

What About SOA and BPM?Business Process Execution Language for Web Services

(BPEL4WS)– An XML standard for defining business processes with

Web Services– Provides high level of abstraction lends itself to

generation from models• Negligible abstraction gap

– UML Profile for Automated Business Processes• Allows UML Class and Activity diagrams to model BPEL• Generate WSDL, BPEL and XSD Schema

Business Process Definition Metamodel being developed– UML2-based metamodel with profile for BPD with

mapping to BPEL4WS

Deploying BPEL4WS

What’s Next?

Deployment

• Once you generate a .bpel file from a model (or otherwise), what to do with it?– Microsoft BizTalk Server 2004– BEA WebLogic Integration (imports BPEL4WS)

– AlphaWorks has BPWS4J engine • Plus, toolkit for transforming UMLBPEL

– Oracle BPEL Process Manager• Engine with Eclipse-based designer

– Open source• e.g. ActiveBPEL, Twister

AlphaWorks BPWS4J

Process execution engine, plus UML Profile WSDL + BPEL toolkit

Oracle BPEL Designer

• Works directly with .bpel files

• Deploys to Oracle BPEL engine

Summary

BPEL4WS Modeling Options

BPMN– Should become standard notation– No underlying MOF-based metamodel

BPDM– Yet another notation, multiple mappings

UML Profile– UML tools unpalatable to business modelers

Proprietary– Can map directly to BPEL4WS

A Practical Application?

Imagine…• Model software development process

with BPMN (CIM)• Extract executable model, based on

available web services (PIM)• Transform BPMN to BPEL4WS and

WSDL (PSM)• Deploy custom process automation to

BPEL4WS execution engine

Questions?

Thank you!

Thank You

3146

Modeling BPEL4WS

Please fill out the speaker evaluation

You can contact me further at …richard.gronback@borland.com

References

[BPEL4WS] Business Process Execution Language for Web Services, Version 1.1, May 05, 2003.  http://www-106.ibm.com/developerworks/webservices/library/ws-bpel/

[BPDM] Business Process Definition Metamodel, Version 1.0.2, August 02, 2004.  http://www.omg.org/cgi-bin/apps/doc?bei/04-08-03.pdf

[BPMN] Business Process Modeling Notation, Version 1.0, May 03, 2004.  http://www.bpmi.org/specifications.esp

[UML2BPEL] K. Mantell, “From UML to BPEL: Model Driven Architecture in a Web Services World” September 09, 2003. http://www-106.ibm.com/developerworks/webservices/library/ws-uml2bpel/