Hi,
As per my understanding, when we take a reference of of any web service, we either go for Add Web Reference or Add Service reference.
1. For Add Web Reference - BizTalk generates the respective schemas along with the port types (which actually corresponds to different operations of the service). So, in this case, we can put these schemas in a seperate Schemas Project & one needs
to take the reference of this schema project.
2. For Add Service Reference - BizTalk generates the respective schemas along with an orchestration (which is actually an empty orchestration) and the binding file (having all the SOAP Action mappings). So, in this case, we can remove the orchestration and
put the schemas in schemas in a seperate Schemas Project & one needs to take the reference of this schema project.
I took the reference as per both the above cases and it worked fine with me (i.e. sticking to the best practice that one should keep all the biztalk artefacts is separate projects.
Hope this will help.
HTH,