Why Do Data Warehouse Projects Run Into Scope Creep?
To quote Bill Inmon (guru and author of several great books on Data Warehousing) “Traditional projects start with requirements and end with data. Data Warehousing projects start with data and end with requirements.” As soon as the project gets under way, users will find new applications, and with it will come new requests for data. Interestingly, these projects often are justified by moving Q&R work away from the ‘data people’. What we’ve seen is that the first thing that happens as soon as the project delivers is that more requests for special queries are submitted to these same ‘data people’. This may appear to undermine the initial business case but actually signals the onset of value creation from the DWH project. 2. Star Schema Versus Entity Relation Model? There has been enormous debate in the community about the merits of different data models. At the risk of over simplifying: ER models tend to have better performance (processing time) for the end user, and are often perceived a
