Borror says the primary use for warehoused data at Daiwa is in analyzing risk factors for investment propositions and credit requests. A crucial part of the population process for all data warehouse projects is bringing together a group that understands the business logic with a technical team that will perform the data migration. Each system within an organization has different knowledge related to specific data sets. If that knowledge is not incorporated into the warehouse, the business logic performed on the data in the analysis phase will be flawed. It's the business knowledge that's difficult.
Someone has to understand the business content to know what corresponds to what.
Clear definitions On the technical side, the first step is field definition, which ensures that accounts or entries from whatever system all use the same identifier. I call a file SONY, London calls it SON, and Tokyo calls it 47395. The master file contains not only cross-references of field names, but also of the way data is stored. Another problem can be fields or recor ds that have been misused by the data entry staff. Sometimes this problem can result from simple human abuse of the system.