Need to state history from different time frames. In highly volatile organizations, it is difficult to get a good perspective on long-term trends. The need to restate the history which reveals trends in a stable structure or view of the organization often requires very complex data manipulation. Data on master files are subject to change. Products change their components and formulation.
Customers change names and addresses.
Sales territories may be realigned. All this results in changing conditions of the original reference information which accompanies and sometimes categorizes the transaction events. Accommodating the change of entities and attributes over time adds tremendous complexity to business data models. In some instances, it can result in nearly twice as many subject entities and tables. So when building a data model for a survivable database, look as far ahead into the future as possible.