Production logistics synchronization towards zero-warehousing intelligent manufacturing

Abstract

Production logistics comprises all logistic processes within an industry ranging from replenishing raw materials to product distribution. As product components become more complicated and individualized, the requirements for production logistics synchronization are rising to ensure that parts and products are delivered at the right time and in the right sequences. However, the existing production logistics process impedes expansion of production capacity under limited industrial space and burdens manufacturers with high operating costs. This thesis proposes the Zero Warehousing Intelligent Manufacturing (ZWIM) as a production logistics mode for manufacturers to reduce non-value-added warehousing operations such as put away and picking and improve production logistics efficiency. The whole thesis tries to explore ZWIM from four aspects. In the first aspect, we comprehensively introduce ZWIM from the concept, practices, principles, and core technologies. A Zero-Warehousing Intelligent Manufacturing Platform (ZWIMP), which combines Internet of Things (IoT) technologies to facilitate logistics operations, is developed to provide logistics services for ZWIM practitioners. The component delivery process of a Hong Kong prefabrication construction project is used to illustrate a primary achievement of ZWIM. The second aspect investigates the automation and information investment for warehousing and ordering cost reduction and their associated influences on logistics performance among a two-echelon supply chain. An integrated investment-production-inventory model is developed to minimize the total logistics cost under the fully automatic warehouse setting and is extended to the case with the partial automatic warehouse. The analytical and numerical results show that the investment can achieve significant cost reduction. All supply chain partners are encouraged to upgrade their ordering operations and the entire warehousing process with information and automation technologies to achieve better performance. The third aspect focuses on the production logistics workflow design under ZWIM. We propose a mobile shelf-based inbound logistics unitization process and solve it through the proposed Synchronized Unitization Approach (SUA), which incorporates real-time production status in logistics decisions. Numerical results show that SUA achieves better cost performance under the real-time production setting. Numerical results also show the managerial insights for mobile shelf deployment and truck delivery decisions. We also propose a cross-docking-based factory logistics unitization process. An approximate dynamic programming approach (ADP), which combines the time-varying and piecewise value function approximation, is proposed to derive the logistics decisions efficiently. Computational experiments indicate that the proposed ADP can derive near-optimal solutions when the problem scale is small and generate high-quality solutions far more efficiently than traditional optimization methods. In the fourth aspect, we investigate the real-time logistics decision synchronization in the component replenishment process for a manufacturing plant, including three levels of storage: the third-party supply hub, the on-site staging area, and the line side buffer. First, the problem is formulated to maximize the overall system cost performance. To satisfy the component delivery requirements, we establish a cyclic inventory and replenishment policy and proof its optimality. Then, based on the policy in the deterministic setting, we propose a revised policy to make the logistics decisions under the dynamic delivery requirement arrival process.