Abstract
Fair definition of system boundary is essential for obtaining reliable results in life cycle assessment (LCA), especially in comparative LCA studies. However, it doesn't seem that a consensus has been reached on an appropriate method for selecting system boundary. This study addresses the development of a consistent method for definition of system boundary using an economic input-output table, which describes all the flows of goods and services between sectors of an economy. The method proposed within this paper 1) is quantitative, 2) is objective 3) is reproducible, 4) is available without detail process-LCI, 5) requires little time and cost, and 6) doesn't overlook any process that significantly influences LCA results. This method is demonstrated on complicated production system of a passenger car in terms of CO2 emissions.
