Information Systems (IS) managers are under increasing pressure to justify the value and contribution of IS expenditures to the productivity, quality, and competitiveness of the organization. This paper examines the need for IS assessment and suggests a comprehensive, IS assessment framework linked to organizational performance using existing IS assessment theory as a base and incorporating measurement concepts from other disciplines. The existing models of IS success are updated to include the emerging IS success dimensions of service quality and work group impact and provide a comprehensive method for organizing the various measures of IS success. In addition, many new measures from recent research are presented to supplement the lists supplied by previous research. Additional research is suggested to advance the IS assessment contingency theory. Such a theory has the potential to contribute to the quality and productivity of the IS function and the larger organization by providing feedback to manage and improve the IS function to better meet the needs of the organization.