A holistic methodology for energy and carbon management of complex product manufacturing

Accounting and management of energy consumption and carbon emissions in manufacturing are essential for enterprises aiming to establish low-carbon supply chains and reduce the costs imposed by carbon taxation. However, complex product manufacturing systems, with multi-component structures, long supply chains and dynamic process variability, limit the precision of Life Cycle Assessment-driven energy and carbon management (ECM) frameworks. In this paper, the Supply Chain Manufacturing System (SCMS) is first introduced, and a holistic methodology is proposed to support system-wide ECM for complex product manufacturing. First, the concept of SCMS is formalized and its energy-carbon characteristics are analyzed. Second, the proportion of energy consumption and the fluctuation of carbon emissions are defined to classify supply chain enterprises with respect to long-term costs and short-term fluctuation risk. Based on the classification, the differentiated management paradigms of SCMS are designed, including data-coupled, period-coupled and full-process-coupled management. Finally, the methodology is verified on a typical automobile SCMS with three representative suppliers. The results show per-unit carbon emission reductions of 13.29, 7.27, and 0.79 kg CO₂ across the three suppliers, indicating that the methodology achieves effective ECM for complex product manufacturing at relatively low cost.