Fact Tables with Different Granularities in #PowerPivot and #BISM #Tabular

A few weeks ago I received a question that inspired me in writing this article about how to handle data at different granularities in PowerPivot and BISM Tabular. I think this is a common pattern when you have a budget table that contains data at an aggregated level (like month and product category) and you want to compare it with sales that are stored at product and day level. This scenario can be handled in a BISM Multidimensional model by using relationship with other attributes in a dimension, but this is not possible in PowerPivot and BISM Tabular because of the lack of attribute relationships in the model.