This is an important question that anyone responsible for a data warehouse should ask periodically and with some frequency as well.
The following table will give you some concrete ideas on what to look for and how to use the metrics.
The details of how you collect these metrics are dependent on your Database but this is definitely a good start:
|Category||Key Question||Sample Measures|
|Data Size||Do we really need to maintain all these data?||% Dormant Data in DW, DM or Source Data; Data size by subject area, tables etc.|
|Demand and Capacity||Do we have enough infrastructure?||HW and Network Usage and heat maps;Most often used data sets; Most often requested help;Concurrent project capacity.|
|Value||Did we solve a business problem sooner?||% on time serviced requests; % on budget; What-if analysis; COE Results|
|Transaction Volume||Are we servicing the most frequent data needs?||Worst performing queries; Better architecture fit for data marts or data clusters;Better end-user training;|