Abstract
Due to the growing concerns of global warming, manufacturing industrialists, particularly in electronics manufacturing, are seeking better methods to evaluate their carbon emission performance. Currently, most studies focus on the calculation of the product carbon footprint through the life cycle. In this paper, a carbon emission analysis model integrating the new evaluation indicator, carbon efficiency, is proposed based on the improved value-stream mapping (VSM) and sensitivity analysis approach. Carbon efficiency which specifically includes the product carbon efficiency and process carbon efficiency is defined conceptually based on the eco-efficiency. For the calculation of carbon efficiency, the improved VSM is employed to map the value and carbon emission stream of the process flow. Product carbon efficiency, as the metric of carbon emission performance of the whole manufacturing system, is actually determined by each individual process. In order to improve the product carbon efficiency by improving processes, sensitivity analysis of the process carbon efficiency is carried out to identify the bottleneck processes and their improvement potential. An application in the printed circuit board enterprise illustrates the proposed model. The results show that it can be implemented conveniently, and it is more economical to update the bottleneck processes than to build a new manufacturing system.
Acknowledgements
Gratitude is extended to the National Science Foundation of China (51075415) and the Special Research Fund for the Doctoral Program of Colleges (20110191110005) for the financial support.