I am assuming this is related to your previous questions about creating that web service setup I advised you on earlier. If not, sorry...
Don't confuse the idea that since you are offering multiple methods that you need multiple exes or separate files. Each web service method is just a method of a project. This project can have multiple files to help you organize the types of methods they are. Like I had mentioned to you before you could have one set of methods that handle authorization in its own authorization.vb file of a single project while you have another set of methods (like methods for handling reservations or something) in a separate file called "reservation.vb". All these different files would be part of the same simple project.
If you need to update something it would just be a matter of changing a method, recompile and then it is instantly live. Very simple, very elegant solution. Essentially a hundred web service methods could all be part of one project consisting of 10 code files without breaking a sweat.
I hope I have given you an idea on how this all would work.