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The pandemic caused by the COVID-19 virus has had negative effects on different industrial sectors, the world economy and especially on Supply Chains. The pandemic revealed the vulnerability of key logistics processes of companies and their Supply Chains as operational risks increased, causing breaks in inventories, production lines and the distribution process caused by increased customer demand. However, this pandemic makes it necessary to reevaluate the models and strategies that companies had established as the standard, and more was needed to face the shortage of components, raw materials and inputs needed to keep the production processes active. Therefore, this article proposes developing a conceptual model under the System Dynamics methodology, which allows identifying the main impacts that the COVID-19 pandemic had on the performance of the Supply Chain through the design of Causal Loop Diagrams. [ABSTRACT FROM AUTHOR]

Supply chain simulation has been used to analyze possible scenarios, and one of the most used techniques is system dynamics, and although there are some literature reviews on this topic, the number of papers has increased in recent years, so it is necessary to analyze trends, locate the most relevant research groups, authors, and papers. This article reports a bibliometric review on the dynamic system applied to the supply chain on engineering and analyzes 519 documents found in the Scopus and Web of Science databases using PRISMA methodology and VosViewer software. Findings indicate that China, the United States of America and the United Kingdom are the countries that produce the most papers, although Cardiff University is the institution with the most consolidated research groups. The most productive authors are Towill, D.R., Naim, M.M. and Rabelo, L., although the most cited are Towill, D.R., Naim, M.M. and Wikner, J., while the Journals that most publish this topic are the International Journal Of Production Research, International Journal Of Production Economics and the Journal of Cleaner Production. [ABSTRACT FROM AUTHOR]

Musculoskeletal disorders (MSDs) are considered the leading cause of occupational disability and loss of productivity. The manufacturing industry is one of the work sectors where workers are most exposed to risk factors that can cause MSDs. This article reports the case of workers in a manufacturing company located in Tijuana, Mexico. This research aims to minimize the ergonomic risk workers are exposed to in the mechanical kick press and packaging stations. Rapid Entire Body Assessment (REBA) and Job Strain Index (JSI) methods are applied to evaluate the risk levels caused by postural load and repetitive movements before and after redesigning the stations. To redesign the stations, an anthropometric study was performed on the workers. The results show that, with the design of the new press station, the level of risk caused by the postural load is reduced from 10 (high) to 1 (negligible), while the level of risk caused by repetitive movements is reduced from 13.5 (high) to 1 (low). In the case of the packaging station, the level of risk caused by postural load was reduced from 9 to 2, while the level of risk caused by repetitive movements remained at 3. It can be concluded that the correct application of different Ergonomics tools allows for eliminating several risk factors. [ABSTRACT FROM AUTHOR]

This paper addresses the reduction of downtime in key operations. It also addresses the continuous improvement in the process without modifying the process flow, applying the DMAIC (Define, Measure, Analyze, Improve and Control) methodology. In which the information of this work will be focused, explaining the activities to be developed to improve the cycle time in the production line and at the same time to be able to cover the new customer demand. It includes in a general way the necessary validation process of the product, objectives delimited by the norms and regulations for the manufacture of medical products are raised. Engineering studies are presented in detail to determine parameters, validations to ensure equipment installations, a protocol with its respective report where statistical studies of capacity and stability of critical processes are shown. As part of the objectives, capacity was increased by 60% in the production line, reducing the cycle time of operations and eliminating bottlenecks through the implementation of new equipment and ergonomic improvements. [ABSTRACT FROM AUTHOR]

The pandemic caused by the COVID-19 virus has had negative effects on different industrial sectors, the world economy and especially on Supply Chains. The pandemic revealed the vulnerability of key logistics processes of companies and their Supply Chains as operational risks increased, causing breaks in inventories, production lines and the distribution process caused by increased customer demand. However, this pandemic makes it necessary to reevaluate the models and strategies that companies had established as the standard, and more was needed to face the shortage of components, raw materials and inputs needed to keep the production processes active. Therefore, this article proposes developing a conceptual model under the System Dynamics methodology, which allows identifying the main impacts that the COVID-19 pandemic had on the performance of the Supply Chain through the design of Causal Loop Diagrams. [ABSTRACT FROM AUTHOR]

This paper proposes a linear search Simultaneous Perturbation Stochastic Approximation (SPSA) algorithm to maximize the signal-to-noise ratio (SNR) index in the least number of iterations and determine which succession measure converges and maximizes the signal-to-noise ratio (SNR) in the least number of iterations. The analysis and validation are performed with experimental simulation and validated with four case studies collected from the literature. The case studies were evaluated in ten experiments with different combinations of the succession measures ak and ck. The results show that the proposed SPSA is an iterative, efficient, and easy to use method to maximize the quality indexes of production processes, which is feasible to implement within the six sigma methodology. Also, the results show that experiments 3 and 5 converge to the best results in the four case studies analyzed. [ABSTRACT FROM AUTHOR]

The pandemic caused by Covid-19 has led university students in Mexico to take their classes online, where they have to interact with furniture and computer equipment different from the one that exists in classrooms. Interaction with such furniture and equipment can be uncomfortable and have an impact on the students’ Academic performance. Therefore, this article aims to determine the impact of Desk / Table design, Chair design, and Human-computer interaction (antecedent variables), as well as the Mental workload (mediating variable) on university students’ Academic performance (consequent variable) during the Covid-19 pandemic. A questionnaire is developed and applied online to 167 university students, and three mediation models were built where seven hypotheses are included. These hypotheses were statistically validated by applying the ordinary least squares regression algorithm. The results indicated that the three antecedent variables have a significant direct effect as well as total effects of 0.21, 0.14, and 0.49, respectively, while total effects of 0.22, 0.17, and 0.49 on the university students’ Academic performance. The indirect effects were negligible. It is suggested that the three antecedent variables play an essential role in the sustainability of university students. [ABSTRACT FROM AUTHOR]