BPEL, XPDL and BPMN

BPEL, XPDL and BPMN

• cbowman

  BPEL supports web services and system to system applications workflow because:

  1. BPEL specifies the behavior of business processes between web services using web services. Messages and partners are both defined using WSDL. BPEL extends WSDL by adding include partnerLink constructs to it.
  2. BPEL does not support human workflow.

  Some people prefer XPDL for human workflow because this is what it is best suited for. XPDL is one of the few BP standards that includes human interactions as part of a business process. XPDL also lacks transaction and fault semantics, making it less than ideal for system-to-system workflows.

  BPMN is a notation that has been mapped to both XPDL and BPEL. BPMN is capable of modeling processes that cannot be represented using BPEL so this might be the reason for the quote about "BPEL-based modeling tools for BPMS systems lacks a lot compared to BPMN based systems". (This quote is also somewhat disturbing - BPEL is not intended for modeling so I'm not sure what a BPEL-based modeling tool implies...)

  Regarding WF, the underlying XML representation is XAML. Why did we choose XAML instead of BPEL or some other standard Simple - XAML enables us to avoid the constraints imposed by a focusing on a single standard (e.g. BPEL lacks human workflow and sub-processes). WF is capable of supporting multiple standards:

  • A BPEL 1.1 import/export tool is currently being tested and will be released later this year.
  • We are in talks with partners to add BPMN modeling for WF
  • I am aware of a couple of projects looking at XPDL and BPSS for WF
  • The custom loader (I believe it becomes available in Beta 2.1) enables us to directly transform a BP standard to an executable representation, possibly enabling support for executable BPEL

  One more thing about XAML - XAML is the same markup language used by WPF. You may have seen XAML referred to as XOML. This is due to two things:

  1. In Beta 1 the XML schema was not compatible with XAML and was referred to as XOML (which is rumored to be an acronym for eXtensible Orchestration Markup Language - it has since ceased to be an acronym (much like SOAP)). The underlying XML schema was changed to XAML in later releases.
  2. Workflows using XML use ".XOML" as the extension. The main reason here is to avoid conflicts if WPF tools and the WF SDK both reside on the same machine.

  HTH,

  John

  
  
  

• Davids Learning

  Hi ;

  Thanks for the quick reply. But what I was really asking about if any tools provided by Microsoft support XPDL import/export.

  
  
  

• AnnNeedsHelp

  Hi,
  
  Started work on graph rewriting using GrGen.NET is a graph rewrite tool. In order to make it work graph model for XPDL and XOML must be defined along with a set of rules for graph rewriting.

  If anyone has experience with defining graph models using GrGen.NET Graph Model Language please help.

  Also you can find documentation about GrGen.NET tool on this address http://www.info.uni-karlsruhe.de/papers/TR_2007_5.pdf

  Fedja
  

  
  

• Denis Pitcher

  John,

  any news/changes on the 'BPMN modeling for WF'

  Will this modeler be integrated in Visual studio

  Regards,

  Kris

  
  

• Eric Eichler

  "We are in talks with partners to add BPMN modeling for WF"

  Are there any partners that have currently done this to date Can you provide your thoughts about approaching a BPMN to XOML conversion given a BPMN modeler tool for which the output XML is known

  
  

• Martin Thwaites

  Hi Remus;

  We are currently in progress of such implementation. Please provide more clarifications about any specific needs or co-operation that might be suggested. Drop me a comment on my personal space.

  
  
  

• JGMiller

  I was wondering if anyone has made progress with the development of a tool to convert a workflow design from XPDL to XOML.

  thanks

  
  

• JimmyS

  Hi Nagy,

  Just a quick reply to one of your queries.

  Ascentn BPM do support XPDL.

  regards

  
  

• N_John

  Ahmed Nagy wrote:

  Hi ; Thanks for the quick reply. But what I was really asking about if any tools provided by Microsoft support XPDL import/export.

  
  
  Hi,
  
  I found no indication that Microsoft is developing that kind of tool.
  
  I'm starting a project that will provide an XPDL export to XOML
  This problem is in fact graph problem where XPDL is based on defining rules on transitions between activities and where XOML rules/transitions are defined thru composite activities.
  Any thoughts on a algorithm for this kind of mapping
  
  
  

• Owend

  Hi John;

  Thank you for the post. I've also checked your blog and it is really wonderful. Couple of questions here...

  * Since BPEL 2.0 is about to release, what about that import/export tool will it support the new BPEL 2.0 specs

  * Regarding roles how's that going to be translated into XMOL

  * You you say that BPEL does not support human workflow It does support it the same way that WWF does by having the Pick and Receive activities which are equivilent to Listen and HandleExternalEvent activities. Am I correct

  * What about XPDL any tools to support that

  Also consider making the features of any Export/Import tool available in components so we can integrate the export/import functionalities into our application.

  Thanks.

  
  
  
• BPEL, XPDL and BPMN