Debugging SSAS stored procedures

Stored procedures offer a really powerful extensibility for Microsoft OLAP. But the more complex the functions get, the more you need debugging capabilities. Of course you will want to put the business logic of your procedure into a separate class file that can be tested and debugged without any of the SQL Server components. But often enough, the problems happens just in the context of the OLAP engine. Usually you're using objects within the Microsoft.AnalysisServices.AdomdServer scope like Set, Expression, Tuple etc. Code that relies on these objects can only be executed in the context of the OLAP engine. This makes testing a lot more complicated.

Below is the procedure for debugging stored procedures by attaching to the OLAP service. You might also want to read the corresponding technet article.