A bi-objective optimization model designed to incorporate temporal equity into emergency material distribution reduced the effect of time loss comparison among demand points by 53.19% while increasing total logistics costs by 13.76% compared to a single-objective cost-focused model, according to an analysis based on real and simulation data from the 2022 COVID-19 lockdown in Changchun.
In the comparative evaluation, incorporating temporal equity constraints resulted in a time loss comparison effect of 57,583 alongside a total logistics cost of 140,000 yuan. In contrast, excluding temporal equity yielded a higher loss comparison effect of 123,010 while incurring a lower logistics cost of 120,000 yuan. To achieve these solutions, the authors developed a bi-objective framework to simultaneously minimize emergency logistics system expenses and the psychological disparity caused by delivery delays across distribution points, solving the formulation through an elite-strategy non-dominated sorting genetic algorithm.
The research addresses operational challenges highlighted during large-scale infectious disease outbreaks, where rapid resource allocation is critical but conventional logistics models often overlook the equity of delivery timing and the psychological toll of uneven distribution. Evaluating the scenario of prolonged lockdown and pervasive pandemic fatigue, the authors concluded that their bi-objective approach balances temporal equity with economic marginal benefit to produce a more humane and equitable emergency supply distribution system.
Subject of Research: Emergency supply distribution center site selection and route planning under temporal equity constraints
Article Title: Emergency material distribution center site selection and route planning under consideration of time equity constraint
Article References: Zhang, C., Sun, H., Zhao, Y., Tian, X., He, J., Tao, J., Xin, X., & Wang, Y. (2026). Emergency material distribution center site selection and route planning under consideration of time equity constraint. International Journal for Equity in Health. https://doi.org/10.1186/s12939-026-03059-8
Image Credits: AI Generated
DOI: 10.1186/s12939-026-03059-8
Keywords: emergency logistics, supply distribution, temporal equity, route planning, optimization model, COVID-19 pandemic, resource allocation, genetic algorithm, Emergency, material, distribution, center
News Source: Courtney Benton. (November 6, 2026). Emergency Supply Model Balances Delivery Timing Equity and Logistics Costs. Scienmag.
