Causal Allocation and Hierarchical Virtual Metering for Product Carbon Footprint Accounting in Shared-Line Textile Manufacturing

In shared-line textile manufacturing, energy records, material transactions, and environmental data are often available only at the workshop or production-line level, while product carbon footprint accounting requires attribution to orders and batches. This study proposes a causal allocation and hierarchical virtual metering method that separates directly attributable quantities, shared resources, and unresolved common residuals. Physical measurements and business records define the actual total, while resource-specific causal drivers distribute only the shared portion. Materials are directly attributed where batch records are available; energy is allocated from the physical line meter to processes and then to orders or batches; and waste is assigned according to its generating mechanism. The method is tested with real production data from a cooperating ramie-textile enterprise by comparing virtual-meter estimates with temporary physical sub-meter measurements and simpler allocation rules. The results show that physically grounded drivers improve allocation accuracy while preserving measured totals. The proposed approach provides a practical and traceable basis for product carbon footprint accounting when permanent sub-metering is incomplete.