Negotiation is a process of cooperative decision-making between parties concerning the resolution of a common dispute. The goal of negotiation is to develop a settlement that is acceptable to both parties. One way to achieve this is to ensure disputants take responsibility for their outcomes and control the disputation process. Most current systems have chosen to model the negotiation process by representing progress made within a negotiation. In this paper we focus on modelling the trade-offs and compromises to made by parties to a legal dispute. A system we have built to model disputes in Australian Family Law uses fuzzy networks, numerical allocation procedures and decomposition hierarchies.