We have a large projects that have nearly 20 modules on it.We want to use WCF for business layer. We think three way to implement WCF our project: Use only one datacontract and one operation contract. Send ClassName, MethodName to operation and create class by reflaction then invoke the method in WCF side. Second way put all modules in one wcf application, and create their data contracts, operation contracts. Third way is create seperate wcf application for each module and host them seperatly. Which one is the best way? I need your ideas. TIA!