We started writing about DFM and DW testing as a winning combination here.

The functional test of the DFM schemas aims at verifying that the multidimensional schema produced for the data mart effectively supports user requirements and it comes in three complementary types, the workload test, the hierarchy test and the conformity test.

The hierarchy test verifies that the functional dependencies represented by hierarchies in the multidimensional schema are actually valid on source data. This test is especially useful in demand-driven approaches to check if the requirements have been correctly understood and modeled.

Hierarchy tests allow two types of errors to be detected: if a hierarchy includes a functional dependency that is contradicted by source data, then either (1) a modeling error has been done and the functional dependency should be removed from the multidimensional schema, or (2) source data are faulty, which should be taken care of by ETL.

In general, even when no such errors are detected, this test can lead designers to discover denormalization issues they were not aware of in source data, which has a significant impact on ETL design.

Related posts:
DFM and DW Testing: A Winning Combination
Functional test of the DFM schemas: the workload test
Functional test of the DFM schemas: the hierarchy test
Functional test of the DFM schemas: the conformity test
Usability test of DFM schemas