The document describes the three components of a life-cycle assessment (inventory analysis, impact analysis, and improvement analysis) as well as scoping activities, presents a brief overview of the development of the life-cycle assessment process, and develops guidelines and principles for implementation of a product life-cycle assessment. The major stages in a life cycle are raw materials acquisition, manufacturing consumer use/reuse/maintenance, and recycle/waste management. The basic steps of performing a life-cycle inventory (defining the goals and system boundaries, including scoping; gathering and developing data; presenting and reviewing data; and interpreting and communicating results) are presented along with the general issues to be addressed. The system boundaries, assumptions, and conventions to be addressed in each stage of the inventory are presented.