To develop an effective CRM system we have to build a Marketing Data Warehouse which contains all available data from the core systems including:
● customer’s data,
● prospect’s data,
● contract’s data,
● accounting’s data,
● product’s data,
● customer’s contacts data,
● campaign’s data,
● web log’s data.
On that data warehouse can build the CRM analytical functions as:
● behavioural prediction models;
● campaign’s measurement;
● customer value measurement;
● and many other models and reports.

The data warehouse building process includes the data-cleaning of the client-base, the analysis of the reliability, completeness, solidity and relevance of the core system’s data. We examine if the disposable core system’s data are sufficient for the developing of CRM functions. We can suggest the modification of the existing database model, or the expansion of stored data in the core data bases.