Life Cycle thinking - sometimes known as the “cradle-to-grave” approach - has become a central feature of modern environmental management and of the developments which underlie the protean concept of Sustainable Development. The basic idea is simple enough (and is closely related to Life Cycle Costing): it is not sufficient, in assessing the environmental performance of a product, merely to look at its use; it is necessary to ask where the materials come from, what energy and other resources are used to make the product; and what happens to it after use.