RCA Open-Source Application (ROSA) is an open-source management accounting application that aims to provide decision support information to managers. Resource consumption accounting (RCA) is a principle-based approach to management accounting that combines German management accounting techniques known as Grenzplankostenrechnung (GPK) with a disciplined form of activity-based costing. ROSA uses resource consumption accounting (RCA) which is internationally recognized as the most robust form of cost management measurement for providing marginal cost analytics.