The four key decisions made during the design of a dimensional model include:
Select the business process.
Declare the grain.
Identify the dimensions.
Identify the facts.
The answers to these questions are determined by considering the needs of the business along with the realities of the underlying source data during the collaborative modeling sessions. Following the business process, grain, dimension, and fact declarations, the design team determines the table and column names, sample domain values, and business rules. Business data governance representatives must participate in this detailed design activity to ensure business buy-in.