Summary The development of the entity relation model of a dimensional data warehouse is really a logical extension of practices that have been in use since for some time. There are a few patterns that occur repeatedly and once these are understood, dimensional analysis can proceed quickly. To some extent, this paper is unsatisfactory. However, I plead innocent by reasons of insanity. While these may or may not fit well into the relational data model, they are surely a bad fit into data modeling tools.
Data warehouses are organic.
They grow continuously and in directions that no one will be able to predict. The strength of the dimensional structure is the ease with which it can support that growth. Thinking of data points as dimensions rather than attributes can make adding new data points much easier. Basically, follow the rule that base data points should be attributes and derivations of the base data points should be another dimension.