Handling web services in an iOS app
Here's a quick and dirty example to illustrate the benefit of the dictionary setup:

- (NSDictionary *)webServiceIDsAndURLs{
    NSDictionary *sillyExampleDictionary = @{ @1 : [NSURL URLWithString:@"http://www.noreagle.com"],
                                              @2 : [NSURL URLWithString:@"http://www.stackOverflow.com"],
                                              @3 : [NSURL URLWithString:@"http://www.etc.com"]};
    return sillyExampleDictionary;
}


...

- (BOOL) webServicesExecution:(NSNumber *) webServiceID webServiceParameters: (NSDictionary*) parameters{
    NSURL *URL = [[self webServiceIDsAndURLs] objectForKey:webServiceID];
    ClassWebService *webService = [[ClassWebService alloc] initWithID:webServiceID URL:URL];

    // see, no lengty switch, yay!

    return YES; // Not sure what you are planning here...
}