Keep your data warehouse ROI justifications focused on the business value that USING the data warehouse is producing, rather than settling for a justification that assumes reports need to be produced and finds the lowest TCO to produce them.
The data warehouse will be an important business asset -- as important as anything if done right. It merits levels of justification and scrutinization reserved for the top three efforts within a company. At such a strategic level of importance, your justifications need to show results that business executives care about -- an increase in income and/or a decrease in expenses.
While not as easy to compute, and possibly not as believable, as a "cost to produce reports" view, speculative data warehouse dollars are getting harder to come by. Executives are less concerned about specific aspects of technology and more interested in finding a solution that will provide substantial productivity gain and competitive advantage.
At the least, look for a solid, forged relationship between what the warehouse is used for and the advantages it gives a business. Yes, these are harder to get arms around. It involves business processes as well as strict data warehouse processes. And yes, it involves little leaps of faith along the way. But ultimately there is a place for the macro approach to data warehouse ROI, which is really business ROI for programs supported by the data warehouse. Someone on the data warehouse staff
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