I have developed an initial service description ontology based on OWL-S. It is an initial version partly because it will doubtless evolve as I learn more from my research, but also because there are some missing pieces. Perhaps the most obvious of these, as I discussed in my presentation last week, is Quality of Service. Part of the reason QoS is missing is because it’s going to be complex to define and I’m not quite sure how to go about it.

I had planned to tackle QoS as the next part of my research; thinking that if I got something in there, no matter how basic, it would be progress. But the other day a thought occurred to me: Measuring and accounting for QoS in service selection is an optimization step — it is not fundamental to being able to compose services together.

So after thinking it over, I decided to take a more logical progression:

1. Determine how to relate a process model to a service description
2. Build a capability to do the service selection & matching and then execute the process
3. Define how to capture quality of service in the service description
4. Figure out how to optimize service selection with QoS as a factor in the selection

This will give me a chance to get some code running to prove that the basic idea is possible, and it will give me a chance to start generating some results I can use for comparison as I progress.

Now I just need to figure out how to relate a process description to service descriptions. I think I’ll be helped in this by the fact that OWL-S represents a service as a process. This might allow me to assert a certain equivalence between the idea of a service and the idea of a process. I’ll need to work on that.