Production-intralogistics synchronization under graduation intelligent manufacturing system

Abstract

In modern factories, intralogistics focuses primarily on managing the material or work-in-progress flow within a factory, and the production aims to create products by processing or assembling raw materials/parts. Production and intralogistics (PiL) are inherently interactional and coupled with each other, presenting a high complexity of planning, scheduling, and execution that plagues practitioners. Meanwhile, frequent uncertainties regarding operations and resources disturb the PiL workflow, and their cascading effects create chaos in the whole system. Moreover, uncoordinated decisions and operations cause PiL mismatch, which inevitably lowers overall productivity and increases cost. This thesis proposes a novel production-intralogistics synchronization (PiLSync) strategy for Industry 4.0 manufacturing operations management under Graduation intelligent Manufacturing System (GiMS). Specifically, this study consists of four modules. Module I develops a five-phase framework of GiMS, including finite meshing, smart digitization, ticket-based queuing, visibility and traceability analytics, and synchronization. GiMS framework effectively fuses the strengths of advanced Industry 4.0 technologies such as industrial Internet-of-Things (IIoT), Cyber-Physical Systems (CPS), and digital twin (DT), with innovative spirits and principles of finite element method (FEM), Out-of-Order (OoO) execution, and the ticketing mode of graduation ceremonies methodologies for establishing CPS factories as the basis for the following modules. Module Ⅱ formulates a graduation-inspired ticketing mechanism as the planning, scheduling, and execution model under GiMS. The proposed mechanism can facilitate real-time, flexible, and resilient decisions and operations in complex and stochastic environments by leveraging the principle of the graduation ticketing mode. Instead of making rigid plans/schedules that are hard to be executed adherently in traditional methods, the ticketing mechanism explicitly incorporates real-time data into the math formulation to ensure the consistency of decision-making and actual real-time situations. Module Ⅲ addresses the PiL problem under uncertainty in a flexible assembly line derived from a real-life central air conditioner manufacturer. This module simultaneously considers different decision authorities and distributed resources of the PiL processes in the graduation-inspired ticketing mechanism. It designs a PiLSync mechanism based on the ticketing principle under GiMS to support real-time and coordinated PiL decision-making with flexibility and resilience at both planning/scheduling and execution/control levels. Module Ⅳ addresses a multi-resource constrained PiL problem motivated by a real-life assembly system that produces customized smart self-service kiosks. By blending the spirit of OoO execution and the graduation-inspired ticketing mechanism, a novel OoO-PiLSync is innovated. OoO spirit adequately governs the complex interactions among resources and constraints under various workshop uncertainties using real-time visibility and traceability. Hence, the proposed OoO-PiLSync effectively manages the PiL operations under multi-resource and operational constraints and attenuates the cascading effect of uncertainty. This thesis contributes to the theoretical research in the realm of CPS factories framework, synchronized production and intralogistics problem, manufacturing complexity and uncertainty management, real-time data-driven methods, as well as quantitative analysis of the benefits of real-time data and the effects of critical factors. It has gone some way towards enhancing the understanding of manufacturing operations management in Industry 4.0 and provides fresh insights for practitioners towards next-generation smart manufacturing.