Decision support systems that capture, preserve, and reuse implicit knowledge can greatly benefit from explicitly using context. The development of this type of system can benefit from a context-based knowledge representation paradigm to be effective in real-world applications. This paper describes how the implementation of the contextual graphs formalism in the AlexDSS system addresses the system's use of context. Contextual graph’s explicit use of context combats the common user interaction problems of irrelevancy and redundancy that plague knowledge-based systems. The development of AlexDSS supports the notion that the contextual graph’s formalism is a viable solution for a real-world decision support system. This paper discusses how contextual graphs are employed in decision support systems.