The provision of timely, accurate, relevant, and concise information for managerial decision making has traditionally represented a challenge to information systems designers. The mass adoption of enterprise resource planning (ERP) systems has multiplied the amount of data being recorded about the movement of inventory in the supply chain. However, this online information requires much off-line manipulation in order for it to be meaningful to managers. In addition, these data are based on physical structures and business models that evolve over time, and thus inevitably a gap opens between the virtual enterprise and reality. Despite the benefits of inventory visibility and expenditure control afforded by ERP systems, managers still require data from other, nonintegrated systems. In this chapter the authors present their research on decision-making support in two manufacturing organisations, with the objective of understanding how these integrated applications support the manager in achieving his or her goals.