The author's thesis statement was, "Modelling the strength of relationships between agents and predicting the behaviour of trading partner agents in a multi agent argumentation system enables agents to build trusted trading partnerships". To develop a relationship aware argumentation system, the following research questions are addressed. How does an agent specify needs and which enactments (i.e., products and services) satisfy the specified needs?, Which opponent agent does an agent select to interact with in an attempt to satisfy a given need?, How does an agent interact (i.e., negotiate) with an opponent agent hopefully to reach an agreement?, How does an agent perform the enactment of a signed commitment, and how does an agent evaluate the enactment that satisfies its needs?, How and when does an agent analyze interaction history, exchanged information and any promises made to predict its opponent agent's behaviour?, How does one integrate the answers to the above five research questions into a complete system? Addressing the above questions, the author presented an argumentation system that enables trading agents to build trusted trading partnerships through argumentation.