In almost every Reporting Services class I teach, I get basically same questions. One of the most popular questions is how do I call a method in a custom assembly from my report. Here are step By step, instructions to do this. 1. Using Visual Studio Create a new Class Library(VB or C#) I am going to name my Project SSRSAssembly 2. Rename your Class1.VB or Class1.CS to ComplexCalculations, presumably you would have your re-usable methods in this class 3. For next step, please use your imagination, ......