SSRS Report Parameters Order

While developing ssrs reports using wcf services as datasource. please make sure that
class, members are decorated with
[MessageContract(IsWrapped = true)]
public class AccountingTaxReportRequest
{
[MessageBodyMember]
public int ProcessMonth { get; set; }
}
so, create the respective number of parameters in the ssrs file. Now in the query string the order of the parameters is important.

best way is to consume the wcf service in a sample application. observe the order of parameters in which they appear there. Follow the same order of parameters, datatype in the ssrs report too.

It saves lot of R & D for you.

Best of luck.