There has been explosive growth in the use of data warehousing technology in the construction of decision support infrastructures. Industrial applications have highlighted the dichotomy between on-line transaction processing and data warehousing, with a focus on read- only ad-hoc analysis of business data [Inmon 1992]. Data warehouse development is based on business processes and associated decision-making tasks, and therefore may result in critical information system components. The design and enhancement of important decision-making activities may be a source of competitive advantage. While some traditional transaction processing systems are purchased “off the shelf,” the promise of competitive advantage may favor custom development of some data warehouse components. Therefore, design tools that support technical development and communication with business users are essential.