A major Executive Support Systems (ESS) design problem is determining ESS requirements. We present the CESS method as a guide for ESS design - with a primary focus on ESS requirements determination and how requirements can be fulfilled using information and communication technologies. The method builds on Quinn and associates´ competing values model of organizational effectiveness and current ESS knowledge. CESS can guide ESS designers in designing ESS that support different managerial roles, i.e. the development of ESS that support managerial cognition and behavior.