Rescheduling of Distributed Manufacturing System with Machine Breakdowns

This study attempts to explore the dynamic scheduling problem from the perspective of operational research optimization. The goal is to propose a rescheduling framework for solving distributed manufacturing systems that consider random machine breakdowns as the production disruption. We establish a mathematical model that can better describe the scheduling of the distributed blocking flowshop. To realize the dynamic scheduling, we adopt an “event-driven” policy and propose a two-stage “predictive-reactive” method consisting of two steps: initial solution pre-generation and rescheduling. In the first stage, a global initial schedule is generated and considers only the deterministic problem, i.e., optimizing the maximum completion time of static distributed blocking flowshop scheduling problems. In the second stage, that is, after the breakdown occurs, the rescheduling mechanism is triggered to seek a new schedule so that both maximum completion time and the stability measure of the system can be optimized. At the breakdown node, the operations of each job are classified and a hybrid rescheduling strategy consisting of “right-shift repair + local reorder” is performed. For local reorder, we designed a discrete memetic algorithm, which embeds the differential evolution concept in its search framework. To test the effectiveness of DMA, comparisons with mainstream algorithms are conducted on instances with different scales. The statistical results show that the ARPDs obtained from DMA are improved by 88%.

From Line to Loop, A Circular 3D Printing Initiative for Upcycling Commercial Fishing Plastics

<p>The current linear use of plastic products follows a take, make and waste process. Commonly used by large scale industries, including the commercial fishing industry, this process results in approximately 8 million tonnes of plastic entering the ocean every year. While the fishing industry supplies livelihoods, a valuable food source and financial capital to millions of people worldwide, it’s also a significant contributor to the ocean plastics crisis. Without effective recycling schemes, an estimated 640,000 tonnes of plastic fishing gear is abandoned, lost or discarded within the ocean every year. New Zealand is no exception to this problem, as China’s waste import ban, as well as a lack of local recycling infrastructures, has resulted in the country’s commercial fishing gear polluting local coastlines as well as islands in the pacific. With the only other option for the plastic fishing gear being landfill, there is a critical need for circular initiatives that upcycle used plastic fishing gear locally into eco-innovative designs. This research examines the issue by investigating how used buoys, aquaculture ropes and fishing nets from New Zealand’s fishing company ‘Sanford’ may be upcycled into eco-innovative designs through distributed manufacturing technologies. It introduces the idea of the circular economy, where plastic fishing gear can be reused within a technical cycle and explores how 3D printing could be part of the solution as it provides local initiatives, low material and energy usage and customisation. Overall, the research follows the research through design based on design criteria approach. Where materials, designs and systems are created under the refined research criteria, to ensure the plastic fishing gear samples are upcycled effectively into eco-innovative designs through 3D printing. The tangible outputs of this research demonstrate how a circular upcycling system that uses distributed manufacturing technologies can create eco-innovative designs and provide a responsible disposal scheme for plastic fishing gear. It provides a new and more sustainable waste management scheme that could be applied to a range of plastic waste streams and diverts materials from entering the environment by continuously reusing them within the economy.</p>

From Line to Loop, A Circular 3D Printing Initiative for Upcycling Commercial Fishing Plastics

<p>The current linear use of plastic products follows a take, make and waste process. Commonly used by large scale industries, including the commercial fishing industry, this process results in approximately 8 million tonnes of plastic entering the ocean every year. While the fishing industry supplies livelihoods, a valuable food source and financial capital to millions of people worldwide, it’s also a significant contributor to the ocean plastics crisis. Without effective recycling schemes, an estimated 640,000 tonnes of plastic fishing gear is abandoned, lost or discarded within the ocean every year. New Zealand is no exception to this problem, as China’s waste import ban, as well as a lack of local recycling infrastructures, has resulted in the country’s commercial fishing gear polluting local coastlines as well as islands in the pacific. With the only other option for the plastic fishing gear being landfill, there is a critical need for circular initiatives that upcycle used plastic fishing gear locally into eco-innovative designs. This research examines the issue by investigating how used buoys, aquaculture ropes and fishing nets from New Zealand’s fishing company ‘Sanford’ may be upcycled into eco-innovative designs through distributed manufacturing technologies. It introduces the idea of the circular economy, where plastic fishing gear can be reused within a technical cycle and explores how 3D printing could be part of the solution as it provides local initiatives, low material and energy usage and customisation. Overall, the research follows the research through design based on design criteria approach. Where materials, designs and systems are created under the refined research criteria, to ensure the plastic fishing gear samples are upcycled effectively into eco-innovative designs through 3D printing. The tangible outputs of this research demonstrate how a circular upcycling system that uses distributed manufacturing technologies can create eco-innovative designs and provide a responsible disposal scheme for plastic fishing gear. It provides a new and more sustainable waste management scheme that could be applied to a range of plastic waste streams and diverts materials from entering the environment by continuously reusing them within the economy.</p>

Blockchain-Empowered Digital Twins Collaboration: Smart Transportation Use Case

Digital twins (DTs) is a promising technology in the revolution of the industry and essential for Industry 4.0. DTs play a vital role in improving distributed manufacturing, providing up-to-date operational data representation of physical assets, supporting decision-making, and avoiding the potential risks in distributed manufacturing systems. Furthermore, DTs need to collaborate within distributed manufacturing systems to predict the risks and reach consensus-based decision-making. However, DTs collaboration suffers from single failure due to attack and connection in a centralized manner, data interoperability, authentication, and scalability. To overcome the above challenges, we have discussed the major high-level requirements for the DTs collaboration. Then, we have proposed a conceptual framework to fulfill the DTs collaboration requirements by using the combination of blockchain, predictive analysis techniques, and DTs technologies. The proposed framework aims to empower more intelligence DTs based on blockchain technology. In particular, we propose a concrete ledger-based collaborative DTs framework that focuses on real-time operational data analytics and distributed consensus algorithms. Furthermore, we describe how the conceptual framework can be applied using smart transportation system use cases, i.e., smart logistics and railway predictive maintenance. Finally, we highlighted the future direction to guide interested researchers in this interesting area.

Adaptive Manufacturing for Healthcare During the COVID-19 Emergency and Beyond

During the COVID-19 pandemic, global health services have faced unprecedented demands. Many key workers in health and social care have experienced crippling shortages of personal protective equipment, and clinical engineers in hospitals have been severely stretched due to insufficient supplies of medical devices and equipment. Many engineers who normally work in other sectors have been redeployed to address the crisis, and they have rapidly improvised solutions to some of the challenges that emerged, using a combination of low-tech and cutting-edge methods. Much publicity has been given to efforts to design new ventilator systems and the production of 3D-printed face shields, but many other devices and systems have been developed or explored. This paper presents a description of efforts to reverse engineer or redesign critical parts, specifically a manifold for an anaesthesia station, a leak port, plasticware for COVID-19 testing, and a syringe pump lock box. The insights obtained from these projects were used to develop a product lifecycle management system based on Aras Innovator, which could with further work be deployed to facilitate future rapid response manufacturing of bespoke hardware for healthcare. The lessons learned could inform plans to exploit distributed manufacturing to secure back-up supply chains for future emergency situations. If applied generally, the concept of distributed manufacturing could give rise to “21st century cottage industries” or “nanofactories,” where high-tech goods are produced locally in small batches.