Enhancing Transparency and Sustainability in E-Commerce Logistics Decision-Making: Quantitative approaches for supply chain management

The growth of e-commerce platforms poses a major challenge for companies, increasing the pressure for efficient and fast logistics processes. Most consumers now resort to buying products and services online on a regular basis. This market push brings different sustainability challenges, ranging from economic to environmental and social perspectives. To drive sustainable development of logistics processes along supply chains, this thesis focuses on presenting novel quantitative models for optimizing crucial aspects of goods distribution. By considering important attributes of such systems that are often neglected when taking decisions for e-commerce businesses, logistics processes can be streamlined for fair and green value chains. Within this multi-objective context, this work focuses on analytical models, firstly tackling the inventory control problem while taking into account product perishability and environmental metrics related to managing stock of such goods. The traditional monetary perspective is paired with carbon emissions for a stochastic bi-objective optimization approach. Enhancing sustainability and transparency in decision-making while taking into account product waste, stockouts are considered with both cost- and service-level approaches. On the other hand, warehousing activities are linked to high turnover rates and shortages of order pickers, underlining the need for improved working conditions in such environments. To support fair order picking, we introduce a new approach for planning of retrieval tasks with the goal of representing the real performance of such systems while improving efficiency and working conditions. We develop new solutions for batching, assignment, and sequencing decisions of order picking tasks while considering physical fatigue and its effect on work performance. A meta-heuristic that leverages such problem characteristics is developed and employed to solve real-size instances. Such contributions highlight the need for inclusion of overlooked performance metrics when optimizing logistics processes. Slight trade-offs from economic optima can positively lead to great reduction of carbon emissions and tangible improvement of worker well-being, thus supporting both short- and long-term sustainable warehousing operations and business development. In addition to providing tools for informed and transparent decision-making for different stages of product distribution, important insights and policies for inbound and outbound logistics activities of e-commerce distribution centers can be derived by focusing on the underlined perspectives.