In these challenging financial times, it is easy for those controlling the purse strings to ask, "Why do we need a data warehouse?"; Particularly among small to medium sized enterprises, where they may believe they are running quite nicely without one.
So what should a manager be observing that gives them clues they need to think about a data warehouse?
1. Your legacy data is expensive to access
You may acquire segments of your business through mergers or acquisitions. You could have historic databases containing old products or services. If it's taking a lot of time (and therefore costing a lot of money) to access this data and make sense of it, then it could be time to migrate it into a data warehouse.
2. Management information is not joined up
You have to get reports from different parts of your business, and they don't seem to agree - even though you operate from the same customer base. The reason for this is that your organisation is not integrating the data correctly and consistently. The best way to integrate data for a single version of the truth is to build a data warehouse.
3. Adhoc reporting is slow
All you wanted was one extra data item adding to an existing report - how come it's taking so long to do? Quite simply your measures are 'point and click' solutions that have their own ETL functions. So whenever a change is required, the whole solution needs to change and be re-ran. A data warehouse will already have the data in it's most useable form. All of the processing will have been done over night, and your analyst just needs to add the new field, query it and present the results.
Data warehouses are a practical and common-sense way of consolidating important information from all over the enterprise. They are expensive to set up, but once implemented, they will give your organisation a high level of reliability and stability.