Universe Design approach - Dimensional Data model

Question

We use a Dimensional data model which has about 15 different models based on Subject areas. Eg: Billing, Claims, Eligibility, etc. Each model has its own Fact table linked to Dimensions, some of which are Conformed dimensions which is present in multiple models. We want to build Universes on top of this model, for creating Crystal Reports and to expose it to the Business Users to create WebI reports through InfoView.
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The Client has already built 15 Universes one for each Subject area_, which has 1 fact table each and many Conformed dimensions with some junk dimensions. When a Report needs data from more than one Universe, we have to link the different Universe queries at Report. <br>
Major drawback with this approach is change management. As our data model will be expanded in future, which in turn makes me to update multiple Universes when, say a Conformed dimension changes; since the Conformed dimension table will be present in multiple Universes.
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Now we are considering the below approaches to have better Architectural design and have easier User interface.
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1. Creating a master Universe for the Dimension tables(here there may be a effort to modify data model to suit linking Dimension tables together). Then to create derived Universes for each Fact table. These derived Universes will be linked back to common dimension Universe. <br>
Maintenance will be easier in this approach, as whenever a Dimension changes I need not update multiple Universes, but as I am linking Universes at Designer level as Master and derived Universes, I am concerned about the Report development if the report needs data from multiple Universes. Then I would be linking u201Cmultiple Linked Universeu201D queries at Report. <br><br>
2. The other option I have is to combine multiple dimension models(Subject areas) into one Universe. By this we will create minimal number of Universes as possible. May be end up creating 5 or 6 Universes, but we will have tough time in maintaining Security of data elements. For instance, at high level a Universe may have Billing and Eligibility data, where I have to maintain strict Security for the User groups, and let only specific users to see/ use all data elements (objects). <br><br>
Hope I have summarized my question well, any inputs from you on the approach you are aware of/ prou2019s and conu2019s of it in terms of time it takes to build, the performance of Report(creating WebI reports through InfoView) is appreciated !!
We want to see which approach makes it better for creating Crystal Reports and when it reaches Business Users who has little patience waiting for a Report and needs best possible interface

Answer 1

There is no one perfect answer for your question.  Universes are more of an art than a science imo.  I can tell you that we have many conformed dimensions joined to multiple facts in a single universe.  The key to this approach is that for each fact table you will need a context.  The advantage to this approach is the ease in which your WebBI users will be able to build reports.  The disadvantage is that Crystal Reports cannot handle multiple contexts so your Universe is basically useless in CR.  For CR, you will need to build Business Views rather than universes.