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BPEL in a Nutshell

This 10 minute 22 second podcast from gives you a short introduction to BPEL and touches on the following themes:

  • Distinction between workflow and business process management
  • Impact of BPEL on BPM software
  • Programing in the Large
  • BPM standardization: WS-BPEL, BPEL4People, BPEL-SPE
  • BPEL in SAP NetWeaver

The podcast is primarily intended for those who want to add BPEL to their vocabularly. Just download the media file and listen to it on your pc’s speakers or transfer it to any mp3 player to accompany you on your next jog, shopping expedition… We propose to follow this up with the following podcasts in the coming weeks:

  1. BPEL in a nutshell (you’re reading it)
  2. BPEL Glossary for Developers
  3. WS-BPEL 2.0 from OASIS – How it has progressed since BPEL 1.1
  4. BPEL4People White Paper Overview
  5. BPEL-SPE – Explanation of the joint SAP/IBM sub-proces white paper

But – if you have other suggestions our ears are tuned-to-the-max so let us know what you want after you’ve listened to this introduction. To read these white papers or to find out about the other standards that SAP supports then you’ll find all you want on the standards pages in SDN. Alan & Ivana *new 27.04.2007 we’ve added this transcript* Historical note before you read the transcript – Just two weeks ago, bpel did indeed get approved and released as an OASIS specification so BPEL is now a truly open standard. (trumpet fanfare). Alan is no longer part of the SAP NetWeaver team but just as committed as ever to interoperability and process management. Reasonable accurate transcript: Good morning. My name is Alan Rickayzen. I am senior product manager within SAP NetWeaver. My background is workflow, both from the consulting and product management point of view and I am one of the authors of the BPEL4People and BPEL-SPE white paper that SAP and IBM published jointly last year. I am with Ivana Trickovic, who is standards architect in SAP’s Industry Standards group. She is also co-author of the BPEL extension papers and participates in the OASIS WS-BPEL technical committee and we’re here to present in a series of podcasts a short overview of BPEL present and future. This series of podcasts will prepare you for the latest developments that are taking place in BPEL and it’s a good time to do this because there are several new developments are on the verge of being made public. In particular BPEL 2.0, which was recently submitted for public review, BPEL4People and BPEL-SPE and the recent commitment at SAP Teched to take SOA into full swing with ERP 2005. In the following podcasts we will go into a little more detail about the inner-workings of BPEL, followed by other podcasts explaining the new core capabilities and finally we will show you what is in store in the way of extensions. But this first podcast is for the completely uninitiated to give a short overview of what BPEL is used for, why it is so important in ERP software and how it completes the SOA picture. BPEL is a de facto standard that we have taken to Oasis to become the primary open standard dealing with business process management. And here it’s worth being a little more precise about this term business process management (BPM). On the one hand, this term is often used to describe realm of discovering, configuring, creating or improving processes, which have business impact. The focus is on ‘Business’. This is independent of whether any software at all is involved in the business or in the processes. This birds-eye view is the realm of the business process expert, and we are not going to look at it here. Instead, lets assume that the business process is automated by some generic software, a motor or engine that drives the processes, giving them transparency and predictability. This is often called ‘workflow’ and using such workflow software you can engineer business processes to match the needs that the business process expert has blue-printed for the company. Workflow is a useful technique with immediate and calculable return on investment so once a company embarks on the workflow they won’t want to turn back. BPEL processes are one particular way of automating such processes, and evolved from the IBM and Microsoft languages WFSL and XLANG, which were designed for what is called ‘programming in the large’. Again, this is a birds-eye view of a system landscape – at a lower altitude than the business process experts. It is a programming language which is used to control the way systems or companies communicate with each other, describing the sequence of activities rather than the detailed nature of the activity itself. However with the advent of SOA, BPEL become one order of magnitude more significant, because it is ideally suited to dictating the sequencing of services – service orchestration. This is something that the traditional world of human workflow struggled with and failed when deployed in this new large scale context. BPEL has become a success because it not only controls the way a process flows, but can identify out-of-context what to do as the services are invoked in what may seem to be an arbitrary order as is the case when different business partners are involved. You’ll see in a future WebCast how BPEL4People and BPEL-SPE bring the two worlds together. It’s important to be honest about expectations. A business expert will model a process with flow-charts, value chains, lists of goals and KPIs but not with BPEL which is an engineering language. Nevertheless, a BPM system based on BPEL is important part of the complete solution. It is analogous to a database software based on SQL. It’s not just an interface but a whole ethos of how to master the goal at hand. Exporting or importing into the BPEL format is not enough. A BPEL engine is a sort of branding, proclaiming that it has been built form the ground up to support this methodology. The fact that SAP NetWeaver contains a BPEL engine at the heart of it means that you can be confident that you have software that based on a tried and tested methodology which is an important cornerstone in enabling real-world business process automation. For example, you can flip the view of the process in the process editor at any time from the graphic view to the BPEL view (XML) because the process engine was built from the word go based on the BPEL standard. This means that the services SAP ERP 2005 publishes in Enterprise Service Repository can be orchestrated in an effective and stable manner. So even though the business process expert does not get as far as modelling the executable processes with all the exception-handling and nitty gritty of an executable process, it is important to know that NetWeaver will handle this the instant this stage of modelling is required. And because this is a standard supported by all major software vendor, any investment you make in automating processes is future-proofed should your software environment change later. Ivana, could you give us a brief overview of the dependencies of BPEL? The BPEL standard, currently version 1.1, is an XML based standard and rather than inventing the wheel it relies on other de facto standards to describe the complete executable picture. In particular it relies on WSDL 1.1 for the description of the Web Services invoked in the process. This fits the SOA philosophy 100%. It relies on XML-SCHEMA 1.0 for the data types, XPATH 1.0 for the query and expression language and of course WS-Addressing for locating the services invoked. BPEL extensions. BPEL is extendable so minor improvements that SAP or other companies have made will be filtered out when exported to other engines. However, many of these extensions will make it to the next release of BPEL 2.0, and by allowing them to be implemented in advance, the engines can deliver the benefits immediately without jeopardizing the stability of the standard. Similarly, new standards can be added on top of BPEL core, without having to be incorporated into the core. This speeds up the availability of major new features, such as human integration and simplifies the implementation of the standard for the different vendors. An important feature of the BPEL specification is Abstract BPEL. This is a set of qualifiers to the language constructs to enable observable behaviour (sometimes called public as opposed to private orchestration) to be defined using this standard. This means that the external behaviour of the process, at least as much as you are willing to divulge, can be documented and publicised to enable partners, for example to use independent software tools for describe how the companies interact in the one process, without having to worry about transposing formats. You can think of the XML of the abstract BPEL as being the basis of a process contract between two between two independent business partners. However, BPEL is primarily an execution language. So BPEL processes composed in SAP NetWeaver Exchange Infrastructure are compiled and transferred to the run-time engine which is actually used to automate and administrate the processes so that the BPEL is not simply used to describe processes but actually pushes the processes through and records and archives their history. This allows the same run-time engine to be shared by software engineered for other purposes, such as is the case with business activity monitoring (BAM) where listening processes monitor windows of opportunity or listen for events which fail to materialize. So to summarize: BPEL is an XML based language to describe the behavioural aspects of business processes. It is a guarantee, that the workflow tool can handle the situation in business environments (analogous to SQL). BPEL is an extensible language, so future extensions can for example, describe human participation in the underlying processes. SAP NetWeaver, on which SAP ERP 2005 is built includes an industrial strength BPEL engine to support large scale processes. You can flip the view in the process modeller to show either the graphic view of the process or the XML view in BPEL. In the next podcast we’ll describe the BPEL standard in more detail, explaining the important unique BPEL constructs, such as correlation or scopes, which make it so well suited as a process execution language. If you have questions relating to this podcast, then please feel free to post them in the SAP NetWeaver forum devoted to business process management on SAP’ developer network at Thank you for listening and enjoy the rest of the day.

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  • I am one of those who despises "bells and whistles" technology on principle, so could you explain in really simple terms how to get access to the "podcasts" for this episode and also the one that Ivana posted ?

    And while you're at it, could you also tell me how to set the clock on my VCR so it reads the current time instead of 12?  (Just kidding ...) 

    • Hi David,
      Bells and whistles have stood the test of time. It's ipods and moog synthesisers that are challenged 😉

      If you right-click on the download media button on the top right side of the blog you can download/save the audio file to your hard disk. From there you simply open it to use your default audio player (assuming your pc has audio).

      Alternatively click on the link directly and it may start playing automatically.

      I have no idea how to transfer it to your vcr but if you replace your vcr with a pvr then that would solve the problem and possibly your clock problem, too 😉

      Seriously: The second podcast in the series by Ivana Trickovic is now working again. There was a broken link that had prevented this for the last two weeks.

      Hope you find the podcast useful. If not, flame me with suggestions for improvements.
      (Thinks... maybe we should release a transcript of the podcast - eventually)

      • When it was first made commercially available, the US talk-show host Johnny Carson had its inventor on his program, "The Tonight Show".

        While the inventor was describing all the musical instruments that the synthesizer could imitate, he was interrupted by a member of the band (I think a trumpet player), who asked the all-important $64,000 question:

        "Yeah, but can it drink?"

        Maybe that's the question that Walldorf has to answer before people will really be willing to accept guided workflow processes.

        • David,

          >>> "Yeah, but can it drink?"
          >>> Maybe that's the question that Walldorf has to answer


          On the serious side: We're talking proven technology here. Otherwise I wouldn't have spent so much time listening to customers at SAP user groups describing how they lever on this.