The success of Japanese group decision making suggested an investigation into some of the concepts involved, an attempt to provide a theoretical framework to explain this success, and the development of a computer architecture to support this style of group decision making. The Japanese style of group decision making relies heavily on the concept of nemawashi, in which a coordinator or facilitator is responsible for moving the group to consensus. An application of Arrow’s theorem provides a theoretical justification for why this approach succeeds. An architecture is developed for a system which provides decision support to the coordinator, and which uses only inexpensive and widely available technology. The system was originally developed as a Portable version of an Entrepreneurs’ Ggroup Decision Support System and was called PEG. PEG provides an integrated system in which a variety of group decision models are readily accessible to the coordinator, and also facilitates communications among the group members and between the group and the coordinator. PEG also provides a method for combining the experts’ quantitative estimates so as to provide a minimum-variance unbiased consensus.