ABSTRACT
This chapter discusses the general issues encountered in every stage of a life-cycle inventory. The data and information that describe the more extensive inputs or outputs should be based on the study purpose, with care taken to ensure that the life-cycle inventory remains a data-driven accounting procedure. Water volume requirements should be included in a life-cycle inventory analysis. Consumptive usage as a life-cycle inventory input is the fraction of total water withdrawal from surface or groundwater sources that either is incorporated into the product, coproducts, or wastes, or is evaporated. The life-cycle inventory includes the energy requirements and emissions generated by the transportation requirements among subsystems for both distribution and disposal of wastes. The fundamentals of life-cycle inventory are based on modeling a system in such a way that calculated values reasonably represent actual occurrences. Some processes generate multiple output streams in addition to waste streams.
