When you say "WFA", are you talking about a Windows Forms application? If so then I suggest that you use "WinForms" if you want an abbreviation. I have been developing .NET applications for about 13 years and I had no idea what "WFA" was. It is definitely not a commonly-used acronym.
Anyway, your question doesn't really make much sense as it is. Connecting a WinForms app to an ASP.NET app without a database? You don't usually connect the two with a database so your question isn't an alternative to anything. Please provide a FULL and CLEAR explanation of what you're actually trying to accomplish rather than how you think you might accomplish it.