Yes. That's very well put.
A master's dissertation needs to, "Contribute to the sum of human knowledge"
(UK Open University wording, IIRC). In other words, you have to describe,
in the dissertation, something that is new or which extends that which is
known. Perhaps the best test for this came from my professor when I was in
the OP's position: if you could answer the question that the dissertation's
hypothesis poses by simply reading up about it in some books and papers,
then it is not a suitable topic for a masters degree.
The OP's suggested title, "Integration informations system in ASP. NET (Web
Services, SOA)" would simply involve reading already existing texts and
presenting what they say. This is not sufficient.
Something that would be interesting would, for example, be, "A proposed set
of standard interfaces for SOA-based automatic library systems*, using
ASP.NET Web Services as an example partial implementation".
* Substitute some environment here of which you have experience (e.g.
Student record systems, room booking systems ..., whatever)
Having said that, an MSc/MA is not an M.Phil or PhD. So the candidate is
not required to perform original research to that extent. For example, you
might simply reinterpret already known evidence in a novel way. It's a fine
distinction, though. In the example I give above, there are some
pre-existing standards that might lend themselves to conversion to an SOA,
for example (e.g. Z39.50 - if someone hasn't already done it).
HTH
Peter