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The use of plastic bottles has become a significant environmental concern, and recycling them has become a priority. Small and medium-sized recycling companies must collect and categorize large volumes of plastic bottles and sell them to larger recycling firms, a process that is time-consuming, costly, and labor-intensive. This manual sorting process can pose health risks, particularly during the COVID-19 pandemic, and can affect worker productivity. To address these issues, this study proposes the development of an automated conveyor belt system that can rapidly and accurately separate plastic bottles by type. The system utilizes an opaque and transparent plastic bottle separation platform, which saves time, cost, and manpower. This system design provides recycling SMEs with a competitive advantage by serving as a practical application model and a prototype with an easy-to-use concept. Key tools employed in this research include product design development (PDD), Kansei engineering, manufacturing process design, controlling system, and fault tree analysis (FTA). The light sensors are critical components in the separation process, detecting the opacity or transparency of the bottles’ surfaces. The proposed prototype’s reliability will be assessed by FTA, which considers all potential failures. This study contributes to the body of knowledge surrounding the integration of conveyor systems and provides valuable information for businesses seeking to optimize their sorting processes. The guidelines developed in this study can serve as a starting point for further research on the integration of conveyors in waste sorting plants.

This paper investigates a vertically differentiated product (VDP) line design problem in both a centralized and decentralized supply chain setting with one manufacturer and one retailer. We study how the product variety decision making in the decentralized setting affects the number of VDPs developed and produced by the manufacturer, as well as the number of products that the retailer will accept from the manufacturer. We show the value of flexibility, timeliness of information, and product development lead time reduction in three market scenarios where the retailer will elect to carry a product only if the product meets a specified target profit. Our results reveal that if the manufacturer faces a long design lead time and designs only one product line, he may be better off not lowering wholesale prices to accommodate the retailer's profit restriction. If design lead time is short, negotiation between manufacturer and retailer along with a side payment could possibly lead to a profit improving solution for both parties. Optimization models and computational results are presented. [ABSTRACT FROM PUBLISHER]

An important decision problem faced by design managers is identifying an appropriate sequence of many interrelated activities. This study presents an effective tool for determining the activity sequence with minimum total feedback length in a design structure matrix. This problem can be modeled as the linear ordering problem with quadratic objective function and is extremely difficult to solve even for small problem instances. We first transform this problem into two equivalent linear integer programming problems, which can be solved exactly when the number of interrelated activities is not large. To provide good solutions for large problem instances, we further develop an exchange-based heuristic. Finally, the usefulness of the proposed methodology is validated through case study, computer experiments, and benchmark analysis. [ABSTRACT FROM PUBLISHER]