Data Warehouses are databases used by decision makers to analyze the status and the development of an organization. Data Warehouses are based on large amounts of data integrated from heterogeneous sources into multi-dimensional, and they are optimized for accessing data in a way that comes natural to human analysts (e.g., OLAP applications).

Data in a Data Warehouse are organized according to the multi-dimensional model, that hinges on the concepts of fact (a focus of interest for the decision-making process, such as sales and orders) and dimension (a coordinate for analyzing a fact, such as time, customer, and product). Each fact is quantified through a set of numerical measures, such as the quantity of product sold, the price of products, etc.

DW design and development require ad hoc methodologies and an appropriate life-cycle.