How can data warehouse planning become a science ? If the regular set of processes defined to plan and asses data warehouse engineering are available, and the same processes are built into a tool in the form of a workflow, then it becomes science. Any reasonably experienced data architect / BI analysts can use the tool, understand and fill up the workflow with data points and create an assessment, plan the model and come out with a prototype to evaluate the design of a prospective data warehouse.
In the Microsoft BI world, till date the most easy and popular tool of choice for planning a data warehouse, in my knowledge, has been the data warehouse modeling worksheet available from Kimball's Data Warehouse Toolkit book. This worksheet helps at the requirements gathering and modeling level, but not much at the planning level.
The motivation of this post is a new tool that has hit the BI market, and the name is WhereScape 3D. Presently as of the draft of this post, this tool is available as a free trial beta. I gave a try to this tool, and it seems quite of the modeling flavor. In my personal opinion, the tool is not that self explanatory even for a BI Analyst to start using it in a fast track manner, it would require the analyst to learn the tool for a day or two and then start capturing requirements and planning for the warehouse. The striking features is the documentation part, and its one of the unique tools I have come across till date that help the user in modeling the requirements itself to plan the DW right from source systems to data mart. You can read more about this tool from here and download the same from here.
At this time, I am not sure too much about how effective is the tool, but I am pretty impressed by the value it aims to bring to the table and that is indeed one area that has not been targeted by BI product vendors till date. I am sure this is the start of a new race where vendors would start converting enterprise class DW to science, rather than restricting it as art !!