This book deals with collaborative planning, an approach to supply chain planning which aims to coordinate planning tasks of independent supply chain partners while respecting their local decision authority. The major contribution of this work is to provide a process model concerned with the decision making and negotiation aspects of collaborative planning. Taking technological means for data exchange as a given, it sketches a detailed picture of a collaborative planning process at the medium-term level of master planning, assuming that mathematical programming models are used by all partners. Building on the planning process, it indicates how financial outcomes and partner incentives are affected by the negotiations of supply quantities between buyers and suppliers, and demonstrates how supply contract terms can be adapted in order to establish a win-win situation for all partners.