2019
Autores
Silva T.; Azevedo A.;
Publicação
Procedia Manufacturing
Abstract
This paper introduces a new research focus for the problem of flow control. Most of the research until this point in this topic comes in the form of heuristics and flow control protocols, from which we can highlight Kanban and CONWIP. These protocols have as common ground the fact that both impact flow by limiting the amount of WIP (work in process) that circulates through a production route. These limits are not static in a sense that one limit defined for a given period will not suffice for all possible conditions the future may entail. Therefore, we need strategies to find which values for the WIP caps are best (according to an optimization target), given a production system state and a customer demand level. We propose the use of a Reinforcement learning (RL) agent and introduce the problem within the framework of a reinforcement learning problem, showing that for a simulated system it is possible to reduce WIP levels up to 43% without losses in throughput (TH). As an introduction to the flow control problem comparisons between push and pull systems are made resorting to the use of discrete event simulations. We simulated a CONWIP and a push protocol and comparisons are made in terms of cycle-time, throughput and customer lead-time. The work points-out that within the field of industrial management research terms such as cycle-time, customer lead-time, and lead-time are sometimes used interchangeably, which may lead to unnecessary confusion and hindered understanding of the subject matter. Specifically, we show that cycle-time reduction does not lead directly to customer lead-time reduction in a make to order environment.
2019
Autores
Simoes, AC; Soares, AL; Barros, AC;
Publicação
ADVANCES IN MANUFACTURING II, VOL 1 - SOLUTIONS FOR INDUSTRY 4.0
Abstract
Today's manufacturing environment is increasingly pressured to higher flexibility induced by uncertain production volumes as well as uncertain product lifetime. A way to improve productivity in a flexible production system is by using a safe and flexible cooperation between robot and operator. Therefore, manufacturing companies are experiencing an increase in human-robot interactions and in the use of collaborative robots (cobots). To make full use of cobots, it is essential to understand the drivers for their adoption as well as how these drivers are aligned with the companies' strategic objectives. By means of in-depth interviews in six companies in Portugal and France, this study provides a comprehensive understanding of the drivers that influence the intent to adopt, or the effective adoption, of cobots and the alignment of these drivers with the strategic objectives of the company. Empirical results reveal "operational efficiency" and "ergonomics and human factors" concerns as important drivers in the adoption intent. In terms of strategic objectives, it was found that drivers are aligned with productivity and flexibility improvement as well as quality improvement strategic objectives. Understanding these drivers can help in motivating manufacturing companies to adopt cobots, in facilitating their adoption, and in reaping the benefits of this technology.
2019
Autores
Dalmarco, G; Ramalho, FR; Barros, AC; Soares, AL;
Publicação
Journal of High Technology Management Research
Abstract
The concept of industry 4.0 (i4.0) encompasses the integration of different technologies into an autonomous, knowledge- and sensor-based, self-regulating production system. Our objective is to synthesize which are the challenges and opportunities of adopting i4.0 from the perspective of technology provider companies. A single-case research was conducted with ten companies at the Portuguese Production Technologies Cluster. Based on i4.0 technologies – Augmented reality; Additive Manufacturing; Big Data; Cloud Computing; Cyber-Physical Systems; Cybersecurity; Smart Robotics; Simulation; and System Integration – interviewees mentioned that the main adoption challenges are the analysis of data generated, integration of new technologies with available equipment and workforce, and computational limitations. The main opportunities are improvements in: efficiency; flexibility; productivity; cybersecurity; quality of products and services; and decision process due to data analysis. Interviewees have also foreseen changes in company's business model through the integration of internal resources with complementary activities of their partners and other cluster companies. © 2019 Elsevier Inc.
2019
Autores
Silva, HD; Soares, AL; Bettoni, A; Francesco, AB; Albertario, S;
Publicação
COLLABORATIVE NETWORKS AND DIGITAL TRANSFORMATION
Abstract
The highly disruptive transformation that digital platforms are imposing on entire sectors of the economy, along with the broad digitalization of industrial business processes, is having an impact on supply chains around the world. To take advantage of this new aggregated market paradigm new business models with a heavy focus on servitization are changing the value proposition of businesses. In this paper, we describe a reference architectural framework designed to support a digital platform fostering the optimization of supply chains by the pairing of unused industrial capacity with production demand. This framework aims at harmonizing stakeholder requirements with specifications of different levels in order to set up a coherent reference blueprint that serves as a starting point for development activities. A four-layer approach is used to articulate between technical components, with the data and tools layers, and the ecosystem, with the business and interfaces layers. The overall architecture and component description is presented as extensions of the initial set of affordances.
2019
Autores
Ferreirinha, L; Baptista, S; Pereira, A; Santos, AS; Bastos, J; Madureira, AM; Varela, MLR;
Publicação
FME TRANSACTIONS
Abstract
Production scheduling is an optimizing problem that can contribute strongly to the competitive capacity of companies producing goods and services. A way to promote the survival and the sustainability of the organizations in this upcoming era of Industry 4.0 (I4.0) is the efficient use of the resources. A complete failure to stage tasks properly can easily lead to a waste of time and resources, which could result in a low level of productivity and high monetary losses. In view of the above, it is essential to analyse and continuously develop new models of production scheduling. This paper intends to present an I4.0 oriented decision support tool to the dynamic scheduling. After a fist solution has been generated, the developed prototype has the ability to create new solutions as tasks leave the system and new ones arrive, in order to minimize a certain measure of performance. Using a single machine environment, the proposed prototype was validated in an in-depth computational study through several instances of dynamic problems with stochastic characteristics. Moreover, a more robust analysis was done, which demonstrated that there is statistical evidence that the proposed prototype performance is better than single method of scheduling and proved the effectiveness of the prototype.
2019
Autores
Bertoluci, R; Ramos, AG; Lopes, M; Bastos, J;
Publicação
Springer Proceedings in Mathematics and Statistics
Abstract
This paper describes a solution method that was created with the objective of obtaining a more efficient finished goods distribution process for a food industry company. The finished goods distribution process involves the use of the companys own fleet to serve a specific group of customers, and the use of outsourcing transportation services that can make direct and transshipment customer deliveries. The complexity of the problem is due to the need to decide which customers should be served by each of the outsourcing transportation services, direct or transshipment, and to find cost efficient solutions for the multiple vehicle routing problems created. First, an original clustering method consisting of a logical division of the customer orders using a delivery ratio based on the transportation unit cost, distance and order weight, is used to define customer clusters by service type. Then, an exact method based on a mixed integer programming model, is used to obtain optimal vehicle routing solutions, for each cluster created. The solution method for the company real instances, proved able to reach the initial proposed objectives and obtain promising results that suggest an average reduction of 34% for the operational costs, when compared to the current distribution model of the company. © 2019, Springer Nature Switzerland AG.
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