Mittwoch, 26. November 2008

JWT welcomes its new mentor!

The whole team of the Eclipse technology project Java Workflow Tooling (JWT) welcomes it's mentor John Graham. After we struggled for the last two years with the formerly unknown Eclipse processes (but nevertheless managed already two releases), we are glad to have some support for all questions now. John is currently in the PMC of the DTP project and has been working as a committer (and PMC Chair) for quite a while now and is therefore more than knowledgable about everything that we need to know about releasing, packaging, building, IP due dilligence and all the other things that are quite difficult to understand at the beginning.

With him we are looking forward to be integrated into Galileo. Our PMC already gave us the approval to get on the release train, so we are currently preparing everything that is necessary in order to be included in Eclipse Galileo in 2009.

Now you might ask: what is JWT about? With the included Workflow Editor (WE) one can model the business processes and workflows which are initial process engine-independent, but soon with the support of several vendors there will be first implementations and adaptations for important process engines that exist in the market. Using the already existing transformations the modeled workflows can easily be transformed into other models (such as into BPMN or STP-IM) or also to generate code e.g. in XPDL. If somebody prefers the SOA world and web services, then it's also possible to generate BPEL code using the friend Workflow Codegeneration framework. Additionally, there are also already first standalone RCP-applications available that build on JWT such as AgilPro.

Donnerstag, 20. November 2008

Eclipse Summit Europe 2008

Right now Eclipse Summit Europe just happens in Ludwigsburg and many many people from all different kinds of projects are here to explain what they are doing, how their tools can be used or simply to chat with other experts about their experiences.

As part of this conference there has been an STP face to face meeting. Since we are closely collaborating with these guys in several other projects, the JWT guys had been there too. And actually it was the first opportunity for the project leads of JWT to meet each other in person. After we now discussed all kind of matters via mailing list or on the telephone for the last two years, it was a pleasure to meet the other one in person for the first time. This was the picture that Anne Jacko (Eclipse EMO) has taken from us when we met for the first time.


During this meeting we also learned to know other people that are part of STP or met people again that we already knew since EclipseCon 2008 or Eclipse Summit Europe 2007.
It was quite interesting for us that also top-level projects that already exist a lot longer than we do, still cope with problems such as "How to organize the website", "How to make builds", etc.
Specific topics of this meeting were about existing components (SCA modeler, the Policy editor, etc.), but also about the collaboration between STP and JWT. There are a lot of touchpoints between the two projects and we hope that in the future we can work much more closely together than we already did in the last month.

But not only this discussion was quite interesting. Much more the different talks were fabulous. Thanks to Oisin (STP PMC Lead) we got a few minutes in the SOA Tools - New and Noteworthy talk which Marc used to explain the basics about JWT. Unfortunately, the keynote in the morning took much longer, so Oisin was supposed to start later which had a direct effect on the time that Marc had open to introduce JWT. During his talk many people left the audience to go to other talks that had just started, but also others came in who were not interested in STP or workflow details at all probably. Nevertheless it gave us a good opportunity to tell people what we are currently working on.

Another thing that was quite interesting was the Google Summer of Code which Eclipse joins every year now. Each student can apply with a specific topic to that program and from the 30 proposal 20-something have been accepted last year. Each student does get a fund of $4,500 from Google for his/her work, and the mentor needs probably something between 1 and 5 hours a week to work with the student together. Thereby it doesn't matter if the student already worked before on the project or is somehow related to the mentor. Therefore, this would be a good opportunity for our students at the University of Augsburg to get some funding for their work. We will consider that and ask our current students to apply in March.

We also learned to know some other projects such as Eclipse Babel or Buckminster that could be very helpful for us. Actually, the usage of Babel will also be mandatory for all Eclipse projects that would like to join the next Eclipse release (3.5, codename Galileo), so we will definitely have a closer look and integrate it with JWT. Buckminster on the other side allows projects to build an RCP-product or Eclipse application using code from different repositories. Thereby it doesn't matter whether these repositories are SVN, CVS, Maven or something else. So especially for the build of AgilPro or other projects that rely on JWT this will be very interesting to use.

There had also been many improvements on the Eclipse plattform or Plugin Development Environment (PDE) which will make work in the future much more easier. These improvements had either already been included in Ganymede (Eclipse 3.4) or are part of the milestones of Galileo.

What was also quite interesting to hear was that after Galileo, there will be two releases in 2010. One for Eclipse 3.6 (codename not known right now) and another one for Eclipse 4.0 (currently work starts in the e4 project). The workbench of Eclipse will be mostly re-written. Therefore, I heard a talk from somebody who said that it should be based on EMF. This is surely a good idea, but the strange thing was that the person who submitted the first version of this EMF-model did not use EMF for more than one year. So at the first moment, I thought, this is probably not good to build a new workbench on the proposal of somebody who didn't completely knew the technology. But afterwards he said that he works closely together with Ed Merks and other EMF committers and project leads, so I guess the EMF model has been reworked quite well.

As you can see on the following picture, the conference was quite crowded. But nevertheless, it's fun, too :-)

After lunch we attended the talk by Janet Campbell about IP for Eclipse Committers. Since we struggled several times with how this process works for our last release, it was great to hear the process explained in more detail and to get all our questions answered. So, hopefully, the work for the next release will be a lot easier.

Alas, after this talk and after lunch we needed to leave the conference already, since we had some other appointments the same day back at the office. So we missed interesting talks such as Modeling Amalgam as a DSL Toolkit or Eclipse Swordfish (and many others of course). Maybe somebody else listened to them and will write a short summary about them, too. If interested, you can find some more pictures from the conference here.

Dienstag, 11. November 2008

How to semantically annotate a process model?

During my research I got confronted with a lot of different approaches how Semantic Business Process Management (SBPM) can be done. This means in the first step, that the process models need a semantic annotation. But what does that mean?

If you model something (and here it doesn't matter whether this is a business process via BPMN, a UML class diagram or a flow chart) you make use of a standard that defines what kind of model elements exist: in BPMN you have Activities, Events, Gateways, etc. In UML class diagrams you have classes, attributes, methods and assoziations.
So these define what the metamodel element is about. There is often no clear defined semantics in a machine-readable way how a Gateway in BPMN or a method in UML shall be used. The semantics of these elements is mostly captured in a textual way.

So for every human who has a little bit of knowledge about BPMN or UML it is mostly clear what these diagrams mean. But what does a computer do with that? Can it "understand" what we model? Sure, you could say, I tell him that each Activity in BPMN shall be executed. Okay, that's fair. But what does it need to execute? What does the label in these Activities mean? And are there e.g. any relations between an Activity in BPMN and e.g. an Action in UML activity diagrams? The PC simply can't say.

That's where the semantic annotation comes into play. Annotation is contemporary English and has two meanings:
(1) a note added by way of comment or explanation
(2) the act of annotating.

As outlined in this session the annotation can be about a whole document (document-level annotation) or refer to just a specifi part of a text (character-level annotations). Additionally, it can be about the constructs defined in a metamodel (metamodel-level annotations) and on elements in the model itself (model-level annotations).

So, with semantic annotation we aim to capture the semantics of the metamodel elements when different representations are used as well as the terms that describe the model elements.

Now you may ask: what for?

Business process models and workflow models have despite their growing usage still some obstacles to cope with:
- they are used for documentation purposes only
- they are often not up-to-date
- they are not executable
- not all processes /workflows in a company are modeled
- there are different (somehow incompatible) representations used in different companies or departments
- several constructs for one real-world entity exist
- and (the other way round) one construct can be used for different purposes

Now I'd like to come to the initial question: how to semantically annotate a process model?

There are several research projects in the world and many of those need a semantic annotation of the process model (for the rest of this blog post I'll only speak about process models and workflows, however, semantic annotation is definitely something used also for other modeling areas such as software or systems engineering).

Yun Lin describes in her dissertation "Semantic Annotation for Process Models" an approach where an additional tool is used that can read an existing process model and one or more ontologies and can then annotate the model elements with concepts of the ontology and store that in an additional file. This approach (also called "Use metadata to bridge models and ontologies" makes it easy to leave the proprietary process model independent so it can be changed in the modeling tool, but once changes are performed the semantic annotation might not be actual any more.

Michael Fellmann and Oliver Thomas describe in their paper "Semantic Business Process Management: Ontology based Process Modeling Using Event-Driven Process Chains" and in a newer version in German I just got to read how semantic process modeling (a synonym for the semantic annotation of process models) can be done. In their approach they also use metadata to describe what each process action in a business process model means. This metadata connects the process model to an ontology that builds on the Suggested Upper Merged Ontology (SUMO) and where not only domain knowledge but also knowledge about the process language is stored (e.g. they have Activities as well as Offer). But in my opinion this approach makes it quite difficult to use existing ontologies: a domain ontology probably won't have concepts such as Process, but will only talk about the domain at hand.
Additionally, it remains somehow unclear how the semantic annotation is done in practice. They say that they use Protégé for ontology creation and in another paper they speak about semantic wikis for storing the relationsships in a process model. But neither of those two makes a semantic annotation possible. That there is a relationship can be seen on the website of one of the authors, where Semantic Business is linked with a semantic wiki.

The problem with both approaches (by Y. Lin and M. Fellmann) seems to me that they always need another tool. How can business managers be persuaded to first model their processes (which they don't seem to like that much) and afterwards also annotate these models in another tool? I guess this could be quite hard.

Therefore, our approach builds on the extension of a single tool. This can bring the problem that one is bound to a single modeling language for which this extension in the tool is created and that is of course not something we should aim for. Therefore, we'll leverage an existing well-known plattform that by now supports several modeling languages and a lot of more things and which usage is still growing more and more: the Eclipse plattform.

Therefore, we'll use the extension points that are one critical element in Eclipse and extend any existing EMF model with a semantic annotation. By this, we are not only bound to a specific modeling language (such as BPMN), but can support the semantic annotation for several existing modeling languages that already exist in Eclipse or will be integrated in Eclipse at a later time.

Our prototypical implementation will be based on the Eclipse project Java Workflow Tooling (JWT) that is a plattform for modeling, execution, simulating, deploying and monitoring any business process or workflow. More details on the project JWT as well as on our mechanism how this semantic annotation is made independent on the underlying metamodel will be described in the next blog post.

Donnerstag, 6. November 2008

Just started...

So, this is the first article in this new blog. This blog will be concerned about personal experiences, many things about programming in general and especially about Eclipse. I'm a project co-lead of the Java Workflow Tooling (JWT) project and will write time and again about things that we experience there.
I'm working as a researcher on my Ph.D. at the Programming distributed Systems lab. My thesis is concerned about how business process and workflow models can be extended by semantic information and how this additional information can be used for other purposes. A list of my current publications can be found here.