BPEL, XPDL and BPMN

Question

 "BPEL is a standard which supports webservices and system to system applications workflow. For more of a human workflow, XPDL promoted by WFMC is the best."

"BPMN is for modelling and supports both XPDL and BPEL. Simple BPEL based modelling tools for BPMS systems lacks a lot compared to BPMN based systems"

Please provide me with your comments on the above statements.

Also that, what standards are been followed in WF.

Regards

Answer 1

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

 

 

Answer 2

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.

 

Answer 3

Hi Nagy,

Just a quick reply to one of your queries.

Ascentn BPM do support XPDL.

regards

Answer 4

Hi ;

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

Answer 5

"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?

Answer 6

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.

Answer 7

John,

 

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

Will this modeler be integrated in Visual studio?

 

Regards,

 

Kris

 

 

Answer 8

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?

Answer 9

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

thanks

Answer 10

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

Answer 11

Hi,

 

Currently I am working in a development of a product in BPM space and investigating serveral modelling and runtime engines for BPM process.

 

Microsoft WF is one of options and having trouble finding out, is there any support for converting XAML into BPEL or XPDL. If it not currently, is there a road map available on these implementations?

 

thanks in advance for your help

 

Answer 12

 

There's for BPEL not for XPDL...check this download link http://www.microsoft.com/downloads/details.aspx?FamilyID=6D0DAF00-F689-4E61-88E6-CBE6F668E6A3&displaylang=en

 

We talked earlier about XPDL support but MS is not providing such thing (till now at least).

 

 

The above link contains command line applications that will import/export from/to BPEL.

 

Regards,
Nagy

 

Answer 13

Hi Ahmed,

 

Thanks for your immediate reply. Is there any tool available from microsoft to create BPEL via web application. In other words, I am looking for an application, which can be used by analyst as a web applicationa and design the workflow.

Later this desinged workflow can be deployed using biztalk server as a runtime engine to execute this workflow.

 

Providing Biztalk dev environment (which actually requires installing full biztalk server) or VS studio to analyst as a tool to design workflow is not an attractive/feasible option for me.

 

If you know of any third party applications provide this feature, I will be interested in.

 

thanks again for your help

 

 

Answer 14

Although Microsoft have given no indication that they will support BPEL, BPMN or XPDL, they have joined as a OMG member. This could show that they are looking to embrace other standards (other than XAML) in the future

 

Most of the BPM pure-play vendors (like K2, PNMsoft, Metastorm, Lombardi..) support both XOML and BPMN/BPEL in some way or another.

 

If I remember correctly: PNMsoft's platform sits on Window Workflow Foundation and has an addition BPEL/BPMN import/export functionality. This might be a way to tranform XAOML into BPEL (and back)

 

Ruth Stark - BPM Analyst

Answer 15

Other linked references:

BPM software, workflow software, bpm tutorial, workflow tutorial, bpmn tutorial

 

Hope these help,

Peter