Thursday, June 14, 2007

Dynamic Composition using Semantic Web Services

As per Wikipedia the workflow is defined as: Workflow at its simplest is the movement of information and/or tasks through a work process. More specifically, workflow is the operational aspect of a work procedure: how tasks are structured, who performs them, what their relative order is, how they are synchronized, how information flows to support the tasks (wordflow) and how tasks are being tracked. As the dimension of time is considered in workflow, workflow considers "throughput" as a distinct measure. Workflow problems can be modeled and analyzed using graph-based formalisms like Petri nets.

Workflow is an intergral part of today's business applications. Where we perform a chain of activities like Order fulfillment, Payment Processing, New Recruit etc. Today SOA, BPM and many others are trying to address the same problem domain.

With Semantic Web Services in place creating a Workflow dynamically seems to be a possible task. Here are few reasons why I see that a possibility:
  1. Ontology Based: Every Service makes an Ontology Commitment. i.e. it finds its place in the Ontology Structure.
  2. No Fixed Messaging Structure: This means each service is capable of using a common understood format for input and output messages.
  3. Meaning Based: Each publisher will publish details along with the Service which conveys meaning of it. This makes the Discovery process more accurate. The only problem will arise if two or more services are published with the same Semantic description. In that case another parameter like region, cost or any other such parameters will be required to make the choice.
Considering these I am in the opinion that dynamic composition is a possibility using Semantic Web Services. In future posts I will elaborate more on this and also the way I see it all coming together.

I am right now in the process of working on a model for Ontology Server. I would love to hear from you this. If you have any thoughts / ideas on Ontology Server I would like to hear from you.

Until Next Time ... :)

5 comments:

Jan said...

Hi,
maybe you get some inspiration from related projects worked on SWS: Adaptive Service Grid more precisely the WSMX , KOMPASS (only in german), arles and certainly METEOR-S.
In my opinion #1 (ASG) is the most interesting.
Jan

Anonymous said...

Hi,
I agree with you idea. But I would like to know what kind of additional description is needed for web services to be incorporated on ontology.
regards

Samir Kumar Mishra said...

You need to add all those parameters which can add meaning to the web services. The idea is to provide more and more information like what kind of input parameters are acceptable, what can be expected as output, is there any pre-condition etc..

Anonymous said...

Hello again
thanks for your reply.
semantic web services is important for run time service binding. But from my understanding dynamic composition is a lot more than that. specially automatically generating abstract process model from user request is the difficult part dynamic composition.how do you think semantically describing web services and creating ontology helps automatic generation of abstract process model?If you are familiar in area of web sevice composition I would like to have more discussion.
regards

Samir Kumar Mishra said...

Anonymous,
Pls feel free to email me on the link provided (top-left) on the blog main page and I will be happy to discuss this with you over email.

Thanks
Samir