Global retail supply chains are heavily reliant on efficient container shipping. This study focuses on how a shipping intermediary such as a fourth-party logistics (4PL) provider can enable efficiency gains in retail container distribution. We consider the assignment of cargo to containers and vessels to accommodate downstream retailer demand, aiming to minimize both environmental and economic costs. We develop an integer optimization model that represents the key decisions of which journeys to select to ship various types, and quantities, of products onto containers of various sizes. We generate problem instances using international supply chain data inspired by two large United Kingdom (UK) retailers. Our model is useful for evaluating the feasibility of coopetition in container shipping, which we define as a contractual agreement with a 4PL, of which consolidation is one operational dimension. We conduct a variety of sensitivity analyses around the cost of fuel, cost of carbon emissions, and under coopetition or competition, to better understand their effects on model outcomes. Although some studies have mentioned that coopetition can prove economically beneficial, our study has shown that for the data and model we consider, the advantages of coopetition are quite limited. Our findings suggest there are limited economic or environmental benefits associated with the competition or coopetition scenarios when only fuel costs increase. The greatest benefits from an environmental perspective occur when joint increases of fuel and CO₂ costs occur, which result in greater environmental co-benefits in the coopetition case. Alternatively, CO₂ cost increases show that competition contexts had greater environmental benefit.

全球零售供应链严重依赖有效的集装箱运输。这项研究的重点是诸如第四方物流（4PL）提供商之类的运输中介如何在零售集装箱分销中提高效率。我们考虑将货物分配到集装箱和船上，以适应下游零售商的需求，旨在最大程度地减少环境和经济成本。我们开发了一个整数优化模型，该模型代表关键决策，即选择哪种旅程将各种类型和数量的产品运送到各种尺寸的容器上。我们使用受英国两家大型零售商启发的国际供应链数据生成问题实例。我们的模型对于评估竞合的可行性非常有用在集装箱运输中，我们将其定义为与4PL的合同协议，其中合并是一个运营方面。我们围绕燃料成本，碳排放成本以及竞争或竞争下进行了各种敏感性分析，以更好地了解它们对模型结果的影响。尽管一些研究提到合作竞争可以证明经济上的好处，但我们的研究表明，对于我们考虑的数据和模型，合作竞争的优势非常有限。我们的研究结果表明，仅燃料成本增加时，与竞争或竞合方案相关的经济或环境效益有限。从环境的角度来看，最大的好处是燃料和CO ₂共同增加时发生成本，在竞合案例中会导致更大的环境共同利益。另外，CO ₂成本增加表明竞争环境具有更大的环境效益。