The introduction of Lean Supply concepts and the subsequent development of the partnership approach have revolutionised the relationships between buyer and seller, in particular the non-adversarial approach to buyer/supplier relationships where the objectives move from win/lose to win/win and the joint maximisation of profits. The book critically appraises the approach and moves beyond partnership sourcing, and attempts to show how inter-firm relationships can be used to develop competitive advantage. This book is written for both practising managers who wish to develop effective commercial relationships, students at both undergraduate and MBA levels, and professional stage students of the CIPS.