Discussion is one of the core activities of group decision making. Though there are many group discussion supporting tools, they only support methods but not efficiently support discussion management due to the lack of discussion process concept. In this paper, a conceptual model to support discussion process in group decision making is proposed in order to develop a computer-mediated group discussion management system (GDMS) by adopting discussion flow concept on linking discussion methods, suggesting meta-discussion structure among unit discussion method(UDM)s that could support specific discussion type, and preparing the managerial role to control discussion flow. Discussion occurred in object-identification process in object-oriented software developments methodology is presented as an application, and a prototype of a web-based GDMS is implemented based on the suggested model.