Since we will be reusing an existing plugin and converting it into a custom workflow activity, we will need the refactored plugin from Refactoring your plugin using a three-layer pattern in this chapter. Alternatively, you can start writing your own custom workflow activity from scratch; in which case, follow the layering examples from the first recipe in this chapter from step 1 to step 31. Make sure you reference the Microsoft.CrmSdk.Workflow NuGet package in your solution. As per most of the custom code recipes, we will be using Visual Studio 2015 to implement the changes.