Planning theorists are often criticised for being insufficiently concerned with the needs of practitioners. The author of this book takes a view of planning which centres around the decision-making process and offers a theoretical approach which takes practice as its starting point. Building on his earlier important work, Planning Theory (Pergamon URPS 1984, first edition, 1973), this book constitutes a further major advance in planning thought, synthesizing the influence of the British IOR School with the American 'rational planning model'. Going beyond previous 'generic' approaches, the work culminates in a consideration of theory and practice in the planning of all forms of environmental intervention.