Packaging governance under stepwise parcel tariffs: A pattern-based cost-modeling framework for e-commerce SMEs

This study examines packaging governance as a managerial lever for improving transport cost efficiency in e-commerce logistics systems, focusing on small and medium-sized enterprises (SMEs). It develops an adoption-oriented, pattern-based cost-modeling framework linking packaging decisions to carrier pricing and freight performance. The framework consolidates orders into recurring size-composition patterns, screens feasible packaging configurations, compares incumbent-compatible policies with exact equal-cardinality catalogs, evaluates fulfillment and transport costs across tariff bands, and translates the selected policy into replenishment requirements. The evidence comprises one year of transaction data from a Thai e-commerce SME, covering 11,938 orders, 24 priced packaging candidates from a 35-pack observed catalog, 201 physical packing trials, exact mixed-integer benchmarks, frozen temporal holdouts, and 5,000 day-block bootstrap pseudo-years. Conditional on the 24 priced candidates, the validated deployable policy comprising 12 packaging stock-keeping units (SKUs) reduces modeled annual packaging-related fulfillment cost by THB 111,692.9 (16.29%) relative to the observed status quo. Shipping-charge reductions account for 81.0% of the gain, and 78.87% of orders move to lower tariff bands. The exact best feasible 12-pack catalog costs THB 97,617.1 less annually than the deployable policy, which retains all eight incumbent codes and uses fixed lookup and fallback rules. The deployable policy also maintains replenishment feasibility, with fill rates above 99.7%. The findings show how carrier tariff thresholds shape shipper packaging rules, while remaining conditional on one firm, one tariff schedule, and incomplete procurement-price coverage.