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- What system holds the truth?
- Which system(s) get notified when a change is made on one of the systems?
- If all systems need to be updated, then each system needs to know how to transform the data to be consumable by the each of the other systems which requires programming many transformations. In the extreme case it would the example above could take five transformations for each of the six systems making for a total of 30 transformation applications.
- How are the changes handled? In real time or in batch? If in batch, what is the latency between batch updates?
- The onus of transferring data between systems becomes a data integration nightmare where some systems have to spend a great deal of resources converting data so that it can be consumed by or received from other systems.
- How does the organization manage access to the data? Perhaps the Warehouse should get access to only a subset of the customer data or shouldn't get any level of access to the Credit Card Processing system.
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