Business Process Management Languages

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Business Process Management Languages
Slinger Jansen Johan Versendaal Pascal van
Ravesteyn
Utrecht University
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Outline

• What are BPM Languages?
• Different languages
• BPEL
• BPML
• BPEL4People
• ebXML
• WSDL
• OWL-S
• Exercise

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History of Competing Standards
Source http//www.radikalfx.com/bpel/usage.html
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BPEL example of Purchase order processing
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Business Process Execution Language

• Introduced by IBM, Microsoft and BEA BPEL for
  Web Services (BPEL4WS, or just BPEL)
• Currently managed by OASIS
• Combines the capabilities of
• IBM's Web services flow language (WSFL) from IBM
  WebSphere Business Integrator
• Microsoft's XLANG as used by Microsoft BizTalk
  Server 2002.
• BPEL includes
• WSFL support for graph-oriented processes,
• XLANG support of structural constructs for
  processes.
• BPEL is designed to support implementation of any
  complex business process, as well as to describe
  interfaces of business processes.

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BPEL and Activity Diagrams

• BPEL is a language
• Not often written, mostly designed with Activity
  Diagrams
• Some typical statements
• Invoke an operation on a Web service (ltinvokegt) 
• Wait for an external message (ltreceivegt)
• Generate a response for input/output (ltreplygt)
• Wait for some time (ltwaitgt)
• Copy data between locations (ltassigngt)
• Indicate that an error occurred or something went
  wrong (ltthrowgt)
• Terminate the entire service instance
  (ltterminategt)

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More Typical BPEL Statements

• Do nothing (ltemptygt)
• Define a sequence of steps to be executed in a
  specific order (ltsequencegt)
• Branch using a "case-statement" (ltswitchgt)
• Define a loop (ltwhilegt)
• Execute one of several alternative paths (ltpickgt)
  
• Indicate that steps should be executed in
  parallel (ltflowgt)
• Indicate fault logic processing via ltthrowgt and
  ltcatchgt
• Define compensation for error recovery -
  implement compensating actions for any
  irreversible actions in error

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Developing BPEL process flow

• BPEL is a process flow language and generally
  developed using a visual editor that creates a
  flow diagram
• Application to application interaction
  (orchestration)
• In develop the sample BPEL process, you will go
  through the following steps
• Step 1 - Get familiar with the involved Web
  services
• Step 2 - Define the WSDL for the BPEL process
• Step 3 - Define partner link types
• Step 4 - Develop the BPEL process
• Define partner links
• Declare variables
• Write the process logic definition
• The language is complete enough to define any
  business process flow

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Step 1 Inventory the Involved Web Services

• Defining partner web services
• Example American and Delta Airlines web
  service which have identical WSDL descriptions

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Step 2 Define WSDL for the BPEL process

• Next, we have to expose the business travel BPEL
  as a Web service. The second step is therefore to
  define the WSDL for it. The process has to
  receive messages from its clients and return
  results.

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Step 3 Define Partner Link Types

• Partner link types represent the interaction
  between a BPEL process and the involved parties,
  which include the Web services the BPEL process
  invokes and the client that invokes the BPEL
  process
• Example
• ltplnkpartnerLinkType name"travelLT"gt
• ltplnkrole name"travelService"gt
• ltplnkportType name"tnsTravelApprova
  lPT" /gt
• lt/plnkrolegt
• ltplnkrole name"travelServiceCustomer"gt
• ltplnkportType name"tnsClientCallbackPT
  " /gt
• lt/plnkrolegt
• lt/plnkpartnerLinkTypegt

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Step 4 Create the Business Process

• Typically, a BPEL process waits for an incoming
  message from the client, which starts the
  execution of the business process. In our example
  the client initiates the BPEL process through
  sending an input message
• Example
• ltprocess name"BusinessTravelProcess" ... gt
• ltpartnerLinksgt
• lt!-- The declaration of partner links
  --gt
• lt/partnerLinksgt
• ltvariablesgt
• lt!-- The declaration of variables --gt
• lt/variablesgt
• ltsequencegt
• lt!-- The definition of the BPEL
  business process main body --gt
• lt/sequencegt
• lt/processgt

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Example Loans (1)
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Example Loans (2)
ltprocess name"loanApprovalProcess"
targetNamespace"http//acme.com/simpleloanprocess
ing" xmlns"http//schemas.xmlsoap.org
/ws/2002/07/business-process/"
xmlnslns"http//loans.org/wsdl/loan-approval"
xmlnsloandef"http//tempuri.org/servic
es/loandefinitions"
xmlnsapns"http//tempuri.org/services/loanapprov
er"gt ltpartnersgt ltpartner name"customer"
serviceLinkType"lnsloanApproveLi
nkType" myRole"approver"/gt
ltpartner name"approver"
serviceLinkType"lnsloanApprovalLinkType"
partnerRole"approver"/gt lt/partnersgt
ltcontainersgt ltcontainer name"request"
messageType"loandefCreditInformationMessage"/gt
ltcontainer name"approvalInfo"
messageType"apnsapprovalMessage"/gt
lt/containersgt ltsequencegt ltreceive
name"receive1" partner"customer"
portType"apnsloanApprovalPT"
operation"approve" container"request"
createInstance"yes"gt lt/receivegt
ltinvoke name"invokeapprover"
partner"approver"
portType"apnsloanApprovalPT"
operation"approve"
inputContainer"request"
outputContainer"approvalInfo"gt lt/invokegt
ltreply name"reply" partner"customer"
portType"apnsloanApprovalPT"
operation"approve" container"approvalInfo"gt
lt/replygt lt/sequencegt lt/processgt
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ACME Example

• You are working for a travel company called
  ACME
• ACME can receive different kinds of requests with
  an itinerary from a customer
• ACME wishes to create a business process called
  ticketOrder
• This process should take in the Itinerary, send
  it to an Airline partner, receive tickets, and
  then send them on to the customer
• ASSIGNMENT Create the BPEL, assume WSDL is
  already defined

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Example ACME Travel Company

• Stolen from IBM

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The process
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• 1 ltprocess name"ticketOrder"gt
• 2 ltpartnersgt
• 3 ltpartner name"customer"
• 4 serviceLinkType"agentLink"
• 5 myRole"agentService"/gt
• 6 ltpartner name"airline"
• 7 serviceLinkType"buyerLink"
• 8 myRole"ticketRequester"
• 9 partnerRole"ticketService"/gt
• 10 lt/partnersgt
• 11 ltcontainersgt
• 12 ltcontainer name"itinerary"
  messageType"itineraryMessage"/gt
• 13 ltcontainer name"tickets"
  messageType"ticketsMessage"/gt
• 14 lt/containersgt
• ltsequencegt

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BPEL 4 People

• Alright, so what if a manual task is involved in
  a process?
• Translation
• Document approval
• Creative processes
• Signature (SOx compliancy approval)
• Etc.
• Just make people Web Services (!?)

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BPEL4People Web Service vs. Human Task
Translation Process
receive document
automatic translation
manual translation
Web Service Endpoint
Abstract Organizational Group
reply translation
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BPMN
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BPEL and BPMN

• BPEL receives direct competition from BPML, but
  BPEL seems to be winning
• Currently a BPMN to BPEL mapping exists
• Impossible to do round-trip-engineering
• BPML has a complete and formalized semantic
• BPEL syntax won out. BPML semantics won out.
• BPEL is evolving slowly into BPML, since BPML is
  formally complete

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WEB SERVICES WORLD
UDDI
SOAP
OWL-S
WSDL
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OWL-S Semantic Mark-up for Web Services

• Automation of service use by software agents
• Ideal full-fledged use of services never before
  encountered
• Discovery, selection, composition, invocation,
  monitoring, ..
• Useful in the real world
• Compatible with industry standards
• Enable reasoning/planning about services
• e.g., On-the-fly composition
• Integrated use with information resources
• Ease of use powerful tools

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OWL-S Ontology Web Language for Services

• Ontology - An explicit representation of the
  meaning of terms in a vocabulary, and their
  relationships

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Key
Publication
Profile
Discovery
Simulation

Selection
Process Model
Verification
Composition

Execution, Interoperation
Grounding

Monitoring, Recovery
Development Deployment Use
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OWL-S Profile to UDDI Mapping
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ebXML e-Business XML

• Just like EDI, but now with XML
• Uses UML

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ebXML Example
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Questions?
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Exercise

• Currently Word, and other software all have their
  own print-facility.
• Create a DocumentPrint webservice using BPEL
  (activity diagram), that generates Postscript
  format for printing.
• Define input partner links
• Define process logic
• Define output partner links
• Suppose the DocumentPrint webservice should also
  handle printing from ERP-system output.