The current and future role of data warehousing in corporate application architecture

Data warehouse systems are widely accepted as a new middleware layer between transactional applications and decision support applications, thereby decoupling systems tailored to an efficient handling of business transactions from systems tailored to an efficient support of business decisions. For companies maintaining direct contact with large numbers of customers, however, a growing number of novel, channel-oriented applications (e.g. e-commerce support, call center support) create a new architectural challenge: traditional transactional applications have to be decoupled from channel-oriented applications to allow for sufficient/flexibility of assigning access/distribution channels to products/services. The paper analyzes the possible extension of the data warehousing approach to application integration, i.e. the potentials of reusing data warehousing methodology and management concepts for decoupling traditional transactional applications and channel-oriented applications. As a foundation for that analysis, an application architecture model along the dimensions ´business process, ´business unit, and ´business function´ is proposed, and relevant application types are located within that model. The extended role of data warehousing that reflects the emergence of novel application types as well as the necessity of online data integration by operational data stores is discussed. Models and findings are based on a close collaboration with several large companies that is institutionalized by the competence centers: ´Data Warehousing Strategy´ and ´Banking Architectures of the Information Age´.