Implementing a Business Process

ibm.com/developerworks/webservices Implementing a Business Process September December 2005

The big picture Rational RequisitePro Rational Portfolio Manager CIO Project Manager 6-2 Understand Risk, Project Costs, and ROI Identify and Manage Projects and Resources Data Modeling Database modeler Model Relational Database Schemas RDB Mapping Presented by IBM developerworks WebSphere Business Integration Modeler Create, Simulate & Analyze As-Is Business Model Business Analyst Create & Manage System Requirements Trace Requirements & Create System Use Case Realizations Architect Create, Simulate, Analyze and Optimize To-Be Business Model UML Rational Software Architect Create Observation Model with KPIs & export to Monitor Create Financial Reports & ROI Estimates Test Model & Implement Services, & expose as Web Services Java Developer BPEL WSDL Rational Functional & Performance Tester Tester Develop Portlets (App UI and Monitor) Portal Developer IBM Rational Team Unifying Platform WebSphere Studio Application Developer Integration Edition Choreograph services using BPEL, WSDL, etc. Configure Human Task Manager (including Ad-Hoc) & Client WSDL EAR DBA Run-time Statistics Observation Model Runtime WBI Server Foundation WebSphere Portal WBI Monitor Deploy/Run Monitor Integration Developer Assemble Solution (BPEL, Human Task Manager, Business Rules, etc) Business Operations Analyst WSDL EAR

The big picture The big picture Business experts design the process in a modeling tool This design can be arbitrarily complex The process design focuses on the business and its resources (people, warehouses, etc.), not on the way the eventual application will work When the business experts are satisfied with the process design, they can export that design to developers 6-3

The big picture When the process design is exported from the modeling tool, three files are generated: BPEL Defines the process flows, branching points, and so forth WSDL Defines the interfaces to the services used by the process XSD Defines the XML data structures (serialized objects) used by the process. 6-4

How we use those files Here's how developers use those files: BPEL Each step in the process is wired to a Web service WSDL If necessary XSD Defines custom data types and maybe used for generating Java beans 6-5

What is BPEL4WS Business Process Execution Language for Web Services Proposed industry standard for Web services choreography A language to specify behavior of business processes As Web services Between Web services 6-6

History of WS-BPEL 7/2002: Original 1.0 BPEL4WS proposal from IBM, Microsoft and BEA. Combined ideas from IBM s WSFL and Microsoft s XLang 4/2003: OASIS Technical Committee formed. Standards-based follow-on to earlier BPEL4WS work 5/2003: Revised 1.1 proposal with contributions from SAP and Siebel 6-7

BPEL is Standards-based BPEL is managed by Oasis Based on WSDL and other XML standards WSDL defines interface of composed service and services used by composite XML Schema and XPath for data context handling and business rules specification BPEL4WS (Business Process Execution Language For Web Services) WSDL (Web Services Description Language) XPath (XML Path Language) XSD (XML Schema) XML 6-8

Elements of a BPEL Process PartnerLinks placeholders for process callers and service providers Variables hold data used in the business process FaultHandlers enclose activities that are performed in cases of error!!! CorrelationSets support process instance identification JavaSnippet Activities subtasks of the process Wait JavaSnippet Throw Control Links define the process' control flow 6-9

The BPEL editor The BPEL editor WebSphere Studio Integration Edition features a state-of-the-art BPEL editor and debugger Everything is done graphically, so it's easy to make changes to your business process If you combine the ability to automate Web services calls with the ability to use legacy applications, BPEL becomes a very powerful tool 6-10

Demo We'll define a process in WBI Modeler and export it to WebSphere Studio as a BPEL document 6-11

BPEL Activities Basic activities allow to define the tasks or steps that make up the business process Structuring activities help to define the control flow of the business process 6-13

BPEL Basic Activities Wait for a message to arrive. Optionally start a new process instance when the message arrives. Pick Wait for one of multiple messages to arrive or for a timeout alarm to go off. Reply Send a message in reply to a message that was received through a. Empty A "no-op" instruction in the business process. a one-way or a requestresponse operation offered by a partner. Terminate Immediately terminate the process instance. 6-14

BPEL Basic Activities Update the values of variables with new data. Staff an interaction with a human user. BPEL Extension Wait Wait for a given time period or until a certain time has passed. J JavaSnippet an inline snippet of Java code. BPEL Extension! Throw Generate a fault from.inside the business process. Subprocess another process life cycle events will be propagated. BPEL Extension 6-15

BPEL Structuring Activities / Elements Flow Holds multiple activities that are performed concurrently. Link Synchronizes two activities that are enclosed in a Flow (i.e, enforces a certain execution order). Sequence Holds multiple activities that are performed sequentially in lexical order. Switch Selects one branch of activity from a set of choices. While Holds a (basic or structuring) activity that is repeated until a success criteriy has been met. Scope Allows for the definition of a nested activity with its own fault handler. 6-16

Composing a Business Process Application Reply Wait Staff Enterprise Application (EAR file) BPEL Staff Business Process Module (JAR file) WSDL 6-17

Wait JavaSnippet JavaSnippet Throw Presented by IBM developerworks Deployment of the Business Process Application ProcessApp.ear ProcessEJB.jar Utility.jar Process.bpel Process-Base.java Process Base Class Process.java Stateless Session Bean Process.wsdl Client.war Business Process Container... Process-Entity.java Entity Bean EAR file Business Process DB WebSphere Administrative Console Manage BPEL container Install/uninstall BPEL applications Start/stop BPEL applications BI Server Foundation Version 5.1 6-18

Elements of a BPEL Process PartnerLinks Variables FaultHandlers!!! CorrelationSets JavaSnippet Activities & Links Wait JavaSnippet Throw 6-19

Partner Links "Placeholder" for a partner No need to specify concrete service endpoints within the model Allows for late binding of partners (at assembly time «build time) Shipping Service send schedule Purchase Order Business Process request shipment start scheduling start price calculation send shipment price Invoice Service Allows for longrunning, stateful interactions with a partner Production Scheduling Service send shipping schedule send invoice 6-20

Partner Links Refer to PartnerLinkTypes Specify roles of each partner <partnerlinks> <partnerlink name="shipperpl partnerlinktype="wsdl1:order-shipperplt" myrole="orderingservice" partnerrole="shipper"/>... </partnerlinks> BPEL File 6-21

Elements of a BPEL Process PartnerLinks Variables FaultHandlers!!! CorrelationSets JavaSnippet Activities & Links Wait JavaSnippet Throw 6-22

Variables Hold data that constitute the state of a process May be received from or sent to partners Can be specified as input or output variables for invoke, receive, and reply activities May hold state data related to the process and never exchanged with partners Associated with WSDL message types 6-23

Elements of a BPEL Process PartnerLinks Variables FaultHandlers!!! CorrelationSets JavaSnippet Activities & Links Wait JavaSnippet Throw 6-24

CorrelationSets Purchase Order Business Process Invoice Service start price calculation send shipment price send invoice 6-25

CorrelationSets Defined by groups of properties Used between partners to identify process instances Values of a correlation set initialized once, thereafter associated with process instance Properties in incoming messages later used to correlate message with process instance <correlationsets> <correlationset name="ordercs" properties="wsdl1:orderno"/>... </correlationsets> BPEL File 6-26

Message Properties: Key to Correlation Property: a globally unique name, associated with an XML Schema simple type PropertyAlias: identifies the location of the property in a message <bpws:property name="ordernumber" type="xsd:string"/> <bpws:propertyalias propertyname="tns:ordernumber" messagetype="tns:productdata" part="ono" query="" /> <message name="productdata"> <part name="ono" type="xsd:string"/> <part name="kind" type="xsd:string"/> <part name="size" type="xsd:string"/> </message> WSDL File 6-27

Elements of a BPEL Process PartnerLinks Variables FaultHandlers!!! CorrelationSets JavaSnippet Activities & Links Wait JavaSnippet Throw 6-28

Fault Handler!!! Associated with a Scope Handles faults thrown in their scope A fault reaching a fault handler means that regular processing within this part of the business process can no longer be successfully completed All active work within the scope will be stopped Specifies activities that must be performed if a fault has been thrown Allows association of different fault handling activities with different kind of faults (Catch blocks for different faults) 6-29

Elements of a BPEL Process PartnerLinks Variables FaultHandlers!!! CorrelationSets JavaSnippet Activities & Links Wait JavaSnippet Throw 6-30

Cross dependencies: Links A <link> can be used to alter the behavior of a <flow>, crossing the boundaries of <sequence> and <flow> as required Links have A source of the link A target of the link When the source completes The link becomes "active" The target is no longer blocked by the link 6-31

Execution mode of a process Microflow Non-interruptible Single unit of work Not persistent No database / message queueing system involved High throughput Long-running process Interruptible Persistent State stored persistently in database Usage of persistent messaging to reliably hold the navigation information of the flow Transacted execution Supports all types of activities (including those not supported in microflows, e.g. human interaction and asynchronous invocations) 6-32

Transactions: Microflow T 0 Reply Reply Fault Transaction Boundary 6-33

Transactions: Long-running process JMS Message Continue Connector T 0 T 1 T 2 T 3 T 4 Reply T 5 6-34

References BPEL4WS Specification 1.1 http://www-106.ibm.com/developerworks/library/wsbpel/ Whitepapers on Process Choreographer from WSDD http://www7b.boulder.ibm.com/wsdd/zones/was/wpc. html Business Process Management and Web Services http://researchweb.watson.ibm.com/journal/sj/412/ley mann.html Article Series "Understanding BPEL4WS" on DeveloperWorks http://www- 106.ibm.com/developerworks/webservices/library/wsbpelcol1/ 6-35

Summary BPEL makes it possible to build flexible processes that are easy to build, test, deploy and modify IBM's BPEL and process modeling tools make these things easy The hard part is converting your existing applications to services Once you've done that, changing a BPEL-defined process is simple 6-36

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