1,720,986 research outputs found
Uncertainty and sensitivity analyses of Models for assessing oxygen deficiency hazard: Preliminary results
No full textAsphyxiation risk due to Oxygen Deficiency Hazard (ODH) can be assessed implementing predictive models of indoor oxygen (O2) level. In the literature, all the models estimating the oxygen concentration by volume (C02) in a working environment are based on a deterministic approach and provide a single-point estimate of C02 as output. However, deterministic model outputs can be uncertain since they can be influenced by a lack of knowledge or incompleteness of information about the exact value of ODH determinants, and/or because mathematical equations could not completely characterize ODH. For these reasons, this paper proposes a study for introducing a stochastic approach in ODH assessment and for performing uncertainty and sensitivity analyses of two existing models. To achieve these objectives, the ODH models were implemented in Microsoft® Excel spreadsheets and @RISK by Palisade was utilized. Some realized cases and simulations are discussed, showing the most interesting results in terms of possible indoor C02 values, their likelihood of occurrence, and the inputs having more effect on the O2 level uncertainty. Attention is also given to the description of implications for safety managers and decision-makers
Management practices to conduct ladle treatment processes in the steel industry: a systematic literature review
No full textIn an increasingly competitive context, the European steel industry has to introduce innovative solutions and focus on high-quality production. A key part of the steelmaking process able to increase the product quality is the secondary metallurgy undertaken in Ladle Furnaces (LFs), i.e. a refractory lined vessel, where steel reheating, alloying, and inclusion removal are performed. To increase the efficiency of this equipment, twin LF stations have been recently introduced. This technology also permits enhancing the quality performance, and reducing energy consumption, adverse environmental impacts, and risks for workers. Management practices can facilitate the achievement of such objectives, representing a low-cost lever for enhancing production systems. For these reasons, we carried out a systematic review in the scientific literature about the management practices that enable an effective conduction of ladle treatment processes in a twin LF and in a traditional LF configuration. Twenty practices are identified and analysed based on a set of factors properly defined for this study. The results show that there is only one practice specific for the twin LF management: this is based on the Case-Based Reasoning method to predict the end temperature of molten steel for improving both energy efficiency and quality level. Regarding a traditional LF, the majority of existing practices are focused on the attainment of product quality benefits and on proposals of models to monitor process parameters, optimise energy consumption, and obtain high-quality products. These results may stimulate companies in the implementation of management practices to effectively conduct ladle treatment processes
Resource Overall Equipment Cost Loss indicator to assess equipment performance and product cost
Full text linkPurpose This paper aims to overcome the inability of both comparing loss costs and accounting for production resource losses of Overall Equipment Effectiveness (OEE)-related approaches. Design/methodology/approach The authors conducted a literature review about the studies focusing on approaches combining OEE with monetary units and/or resource issues. The authors developed an approach based on Overall Equipment Cost Loss (OECL), introducing a component for the production resource consumption of a machine. A real case study about a smart multicenter three-spindle machine is used to test the applicability of the approach. Findings The paper proposes Resource Overall Equipment Cost Loss (ROECL), i.e. a new KPI expressed in monetary units that represents the total cost of losses (including production resource ones) caused by inefficiencies and deviations of the machine or equipment from its optimal operating status occurring over a specific time period. ROECL enables to quantify the variation of the product cost occurring when a machine or equipment changes its health status and to determine the actual product cost for a given production order. In the analysed case study, the most critical production orders showed an actual production cost about 60% higher than the minimal cost possible under the most efficient operating conditions. Originality/value The proposed approach may support both production and cost accounting managers during the identification of areas requiring attention and representing opportunities for improvement in terms of availability, performance, quality, and resource losses
Wearable devices for ergonomics: A systematic literature review
Full text linkWearable devices are pervasive solutions for increasing work efficiency, improving workers’ well-being, and creating interactions between users and the environment anytime and anywhere. Although several studies on their use in various fields have been performed, there are no systematic reviews on their utilisation in ergonomics. Therefore, we conducted a systematic review to identify wearable devices proposed in the scientific literature for ergonomic purposes and analyse how they can support the improvement of ergonomic conditions. Twenty-eight papers were retrieved and analysed thanks to eleven comparison dimensions related to ergonomic factors, purposes, and criteria, populations, application and validation. The majority of the available devices are sensor systems composed of different types and numbers of sensors located in diverse body parts. These solutions also represent the technology most frequently employed for monitoring and reducing the risk of awkward postures. In addition, smartwatches, body-mounted smartphones, insole pressure systems, and vibrotactile feedback interfaces have been developed for evaluating and/or controlling physical loads or postures. The main results and the defined framework of analysis provide an overview of the state of the art of smart wearables in ergonomics, support the selection of the most suitable ones in industrial and non-industrial settings, and suggest future research directions
Oxygen deficiency hazard in confined spaces in the steel industry: assessment through predictive models
No full textObjective. In the steel industry, performing activities in confined spaces where potential oxygen displacement can occur may expose workers to fatal consequences. To the best of our knowledge, no quantitative exposure assessment of oxygen deficiency in steel industry confined spaces is available in the literature. To overcome this gap, we performed oxygen deficiency hazard (ODH) assessments in real confined spaces using two existing models to identify the most critical parameters responsible for ODH, and suggest controls for mitigating the asphyxiation risk. Methods. We applied a well-mixed model and a near field–far field approach to estimate the indoor oxygen level with time during and following release of simple asphyxiants. Model inputs were mainly gathered thanks to audits and instrumental tests in three firms. Results. The most severe ODH exposures are posed in spaces with restricted volume and where accidental releases of inert gases can occur. Such exposures can be controlled through early release detections and augmented reality systems. Conclusions. ODH assessments in confined spaces of steel firms allow the identification of the most critical parameters from an oxygen depletion perspective, focusing on which data need careful measurement, and help to establish controls compatible with the operations conducted in these areas
Assessing the Sustainability Impact of Improving Secondary Steel Production: Lessons Learned from an Italian Plant
Full text linkThis work presents a sustainability assessment approach to evaluate technological innovations in secondary steel production making use of Electric Arc Furnace (EAF) technology. The assessment covers the environmental, social, and economic dimensions of sustainability by combining different tools (Life Cycle Assessment and Analytic Hierarchy Process), and also provides an integrated assessment of the overall sustainability. The approach, which can also be used to support decision-making, has been applied to a real case study of a steel plant located in Northern Italy. In the case study, environmental sustainability is positively impacted mainly by increased metal yield and reduced furnace energy consumption. The greatest social sustainability benefits are mainly related to improved ergonomic and safety conditions for workers (reduced demand for physical effort, manual handling and repetitiveness, and lower risk of accidents), as a consequence of the introduction of Industry 4.0 technologies. Regarding economic sustainability, a positive impact related to reduced cycle time, increased metal yield and quality yield, reduced maintenance and quality control costs was observed. The integrated assessment of the overall sustainability has proven to be a viable approach to manage trade-offs between the different dimensions of sustainability
Optimization of Cutting Modes During Sustainable Machining of Products Based on Economic Criteria
No full textThe sustainable manufacturing and machining concept using functionally-oriented technologies involves design and technological, economic, social, and environmental dimensions. Currently, rational approaches in the environmental direction are primarily based on effectively recycling cutting tools and chips to minimize the consumption of cutting fluids and energy. However, developing functionally-oriented technologies using economic criteria improves product competitiveness, increases machining productivity, and ensures the choice of rational cutting modes while manufacturing machine parts. The optimization technique of cutting modes during parts machining according to economic criteria using Markov chains was suggested for the first time. The target function is the maximum machining time in specified technological operations or certain technological steps during part manufacturing. It is determined according to regulated reliability indicators, e.g., gamma-percentile operating times to failure as a primary parameter of dependability. Adopting the developed technique in mechanical engineering practice will allow the optimization of cutting modes of parts machining according to regulated reliability indicators due to the operational conditions
Confined space risk management in steel industry: Towards the adoption of Industry 4.0 technologies
No full textConfined spaces are high-risk industrial working areas, since serious and fatal injuries occur with a certain frequency and repetitive scenarios. Although these spaces are “ubiquitous throughout industry”, steel industry represents an interesting field of investigation because performing maintenance and manufacturing activities in confined spaces is one of the most common causes of accidents, also fatal, in this industry. In addition, steel plants are characterised by a significant number of confined spaces, quite varied in terms of features, types, and risks. However, to the best of our knowledge, scientific papers focusing on the risk management in confined spaces in the steel industry are not available in the literature. For this reason, the objectives of this paper are to: (1) identify the confined spaces that are typically present in a steel company, (2) provide guidelines on how to assess and manage risks in these spaces, and (3) propose some possible Industry 4.0 technologies to effectively reduce and control the risks. To achieve these objectives, we conducted in-depth case studies in 3 Italian steel firms. We gathered data thanks to an ad hoc questionnaire, detailed audits, and instrumental tests in identified confined spaces. Finally, a focus group was organised for reviewing and discussing collected data, comparing the obtained findings, and developing guidelines for risk management
Composite Indicators to Measure Quality of Working Life in Europe: A Systematic Review
Full text linkIn the last two decades, Quality of Working Life (QWL) has become a core element of the European social model and the European Employment Strategy. “More and better jobs” is a strategic goal promoted within Europe for emphasising the attention in QWL. However, there is a large debate in the literature on the definition of QWL, its dimensions, and consequently on the methods to use for its measurement. To the best of our knowledge, the systematic reviews currently available in the literature on QWL measurement in European organisations investigate only a particular industry and/or working population. Moreover, they do not focus specifically on composite indicators, although they appear promising in facilitating QWL understanding and comparisons for supporting decision-makers and policy makers. To overcome these gaps, we conducted a systematic review to identify composite indicators for measuring QWL in European organisations. The review returned 19 studies that are analysed based on a set of factors related to QWL locutions, index name, geographical area, industry or population, level of analysis, dimensions, type of data, inputs, outputs, and test and/or validation. The results highlight a significant heterogeneity among the indicators, confirming the lack of an agreed upon QWL composite indicator for Europe. Such heterogeneity concerns also QWL dimensions. A critical comparison of the different composite indicators is provided, along with a unifying proposal of QWL macro-dimensions. Several gaps in the literature are pointed out suggesting directions for future research
A multi–objective decision making model for machine tools selection
No full textThe metal machining sector plays an important role in the Italian economy, with numerous small and medium sized companies usually grouped in clusters. In recent years, machine tools have gone through remarkable technological innovations which, on one side, have widened their possible context of use. On the other side, the selection of the machine technology to be adopted within the production processes has become more complex and riskier. The paper proposes a structured Analytic Hierarchy Process decision–making model for supporting the machine tools selection in the machining sector. The model has been developed in collaboration with several machine tools producers located in Northern Italy and has been validated through its application in several real case studies
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