Various information systems have evolved to support the decision making process. There are decision support systems (DSS), executive information systems (EIS), artificially intelligent systems (AIS), and integrated combinations of these systems. Each of the individual systems supports particular phases and steps of the decision making process, but none of the individual systems supports the entire process in an integrated and complete manner. The integrated systems alleviate the support deficiencies, and each of the integration approaches has specific advantages and disadvantages. By studying these advantages and disadvantages, researchers and practitioners can better design, develop, and implement robust decision making support systems. This chapter facilitates such study by presenting and illustrating the underlying information system architectures for robust decision making support.