This is the first wave of business intelligence (BI). IT needed to separate operational data and databases from its origin for the following reasons:

• Keep data changes history. Some operational applications purge the data after a while.
• When users wanted to report on the application's data, they were often affecting the performance of the system. IT replicated the operational data to another server to avoid any performance impact on applications.
• Things got more complex when users wanted to do analysis and reports on databases from multiple enterprise's applications. IT had to replicate all the needed systems and make them speak together. This implied that new structures had to be built and new patterns emerged from there: star schemas, decision support systems (DSS), OLAP cubes, and so on.