An information system that supports business or organizational decision-making activities.

Sprague [1] defines a properly termed DSS as follows:

1. DSS tends to be aimed at the less well structured, underspecified problem that upper level managers typically face;
2. DSS attempts to combine the use of models or analytic techniques with traditional data access and retrieval functions;
3. DSS specifically focuses on features which make them easy to use by non-computer-proficient people in an interactive mode; and
4. DSS emphasizes flexibility and adaptability to accommodate changes in the environment and the decision making approach of the user.

[1] Sprague, R;(1980). “A Framework for the Development of Decision Support Systems.” MIS Quarterly. Vol. 4, No. 4, pp.1-25.