Data warehousing (DWH) projects are among the most expensive projects of companies in the financial industry. Problems like budget overruns and low end-user acceptance lead to the assumption that despite intensive research over the last two decades the relevant elements determining the success of such projects are not sufficiently investigated. On the basis of a case study about the implementation of a group-wide DWH the author analysis the existence of those still inadequately considered success factors. One challenging hurdle that project members have to clear is the complete fulfillment of interface specifications elaborated during conceptual modeling phase. The author chooses an interdisciplinary approach that involves established language theories and applies them to real-life observations in the case study to identify the necessary prerequisites. Subsequently rooms for improvement in the project approach are derived to guarantee a successful knowledge transfer among project members. Especially personal communication is essential to ensure the project’s success and to increase efficiency in DWH projects.