From User Requirements to Conceptual Design in Warehouse Design: A Survey

Background

The DW is acknowledged as one of the most complex information system modules and its design and maintenance is characterized by several complexity factors that determined, in the early stages of this discipline, a high percentage of real project failures. A clear classification of the critical factors of data warehousing projects was already available in 1997 when three different risk categories were identified (Demarest, 1997), namely socio-technical i.e. related to the impact a DW has on the decisional processes and political equilibriums, technological i.e. related to the usage of new and continuously evolving technologies, and design-related i.e. related to the peculiarities of this kind of systems. The awareness of the critical nature of the problems and the experience accumulated by practitioners determined the development of different design methodologies and the adoption of proper life-cycles that can increase the probability of completing the project and fulfill the user requirements.

The choice of a correct life-cycle for the DW must take into account the specificities of this kind of system, that according to Giorgini et al. (2007), are summarized as follows:

• a)

  DWs rely on operational databases that represent the sources of the data.

• b)

  User requirements are difficult to collect and usually change during the project.

• c)

  DW projects are usually huge projects: the average time for their construction is 12 to 36 months and their average cost ranges from 0.5 to 10 million dollars.

• d)

  Managers are demanding users that require reliable results in a time compatible with business needs.