Business information systems can be either designed as custom applications or purchased as off-the-shelf standard solutions. The development of custom applications is generally expensive and is often plagued by uncertainties, such as the selection of appropriate development tools, the duration of the development cycle, or the difficulties involved in assessing costs. Thus, empirical surveys have shown that between half to two-thirds of information systems projects fail. The current tendency to shift from individual development to standardized, prepackaged software solutions is therefore not surprising.