Host: The Institute of Life Cycle Assessment, Japan
In ISO 14040 series, it is defined that the LCA scope should be determined at the first step of an LCA case study. However, due to the difficulty in collecting the reliable data of all the relevant processes, it is hard to compose the proper life cycle of a product at the first step of LCA. In this paper, considering the cost performance and the result precision in practical LCA case studies, a general and consistent method about how to define the system boundary and compose the proper life cycle is proposed. It uses the matrix method and the Input-Output Analysis (IOA) method. By this method, the life cycle of a product is composed of all the essential relevant processes, which provides the result of LCA with high precision. And the life cycle is composed of only the essential relevant unit processes, which makes the LCA case study to be simplified and of low cost.
