My last week was spent in comparing three tools for testing the SOA artifacts, so that we can propose the same to our customers.
The three were
1. HP Quality Center along with QTP (which my current customer owns)
2. iTKO LISA
3. Oracle's CAVS
My understanding and verdict:
If the Enterprieses really want to have their SOA artifacts validated (in simple terms: web-services, BPEL models, etc tested) they need to use iTKO LISA, as it can work on its own, also can compliment the existing testing/validation tools in the landscape. For example, it can provide the results to the test management tools like HP Quality Center, unless, of course, the customer also has HP Service Test.
If the customer is having HP QTP - then getting LISA or Service Test is a must; as QTP is designed and sold only for the purpose of testing the UI, not the internal functioning.
Oracle's CAVS is for testing the "Hello World" programs - provides only black box testing of XMLs, but cannot provide the needed details internal bottlenecks and failure details.
Of course, what I say is a broad outline and the results vary from case to case basis.