I'm not sure I entirely understand your argument for an ODS in this context. The only difference between that and the warehouse is that the ODS may not encompass the whole enterprise. Assuming that you would still want to have an enterprise-wide data warehouse, the ODS in this context seems to be redundant. I guess what I'm asking is how is it not a data warehouse

I'm also confused about what operational functions (updates etc) you would want to apply in the ODS. Surely any updates should be applied back at the source system.

Lastly if the data marts are being fed from the ODS (as illustrated in the diagram) then what is the data warehouse used for. Shouldn't the data warehouse be used as the one holy sacred supplier of all data for reporting?

Sorry I don't mean to be so negative, data warehouse and data mart design is always very open to interpretation. Thanks for the article it has given me some new angles to consider.