1,720,979 research outputs found
Spare parts management with Additive Manufacturing (AM): a critical review
Full text linkAdditive Manufacturing (AM) is a promising technology for producing spare parts, due to the wide variety of forms and materials that can be used and their enhanced mechanical properties. Given these features and the low lead times compared to classical manufacturing (CM), AM is now being investigated for the management of spare parts. This literature stream is relatively new, with many works based on different hypotheses (e.g., the reliability of AM parts) and with different conclusions. This critical literature review provides practitioners with information on the models available, their findings, and their limitations. Further research directions are also identified
Indoor Environmental Quality (IEQ): A Comparison between TOPSIS- and PROMETHEE-Based Approaches for Indirect Eliciting of Category Weights
Full text linkIndoor Environmental Quality (IEQ) has received a great deal of attention in recent years due to the relationship between worker comfort and productivity. Many academics have studied IEQ from both a building design and an IEQ assessment perspective. This latter line of research has mostly used direct eliciting to obtain weights assigned to IEQ categories such as thermal comfort, visual comfort, acoustic comfort, and indoor air quality. We found only one application of indirect eliciting in the literature. Such indirect eliciting operates without the need for imprecise direct weighing and requires only comfort evaluations, which is in line with the Industry 5.0 paradigm of individual, dynamic, and integrated IEQ evaluation. In this paper, we use a case study to compare the only indirect eliciting model already applied to IEQ, based on TOPSIS, to an indirect eliciting method based on PROMETHEE and to a classical direct eliciting method (AHP). The results demonstrate the superiority of indirect eliciting in reconstructing individual preferences related to perceived global comfort
Additive or Conventional Manufacturing as spare parts manufacturing technology: the impact of qualification tests
No full textAdditive manufacturing (AM) has recently emerged as a potential breakthrough technology in the world of spare parts management. Thanks to its characteristics, it can enable the production of spare parts with very low production lead time, with considerable impacts in terms of inventory levels. Some researchers have recently focused on the topic, trying to understand whether it is convenient to produce spare parts in AM or in Conventional Manufacturing (CM) techniques. However, all these works neglect a crucial aspect. Spare parts, before being utilized, need to be qualified from certified entities. The qualification requirements vary depending on the criticality of the spare parts, but they are all associated with non-negligible costs, which however have been completely neglected so far. In this work, to overcome this gap we develop a mathematical model that can support managers and practitioners in choosing the most convenient manufacturing technology (i.e. AM or CM) considering for the first time the qualification costs. The model proposed has been applied to a real case study to demonstrate its applicability. Copyright (c) 2023 The Authors
Indoor Positioning Systems in Logistics: A Review
Full text linkBackground: Indoor Positioning Systems (IPS) have gained increasing relevance in logistics, offering solutions for safety enhancement, intralogistics management, and material flow control across various environments such as industrial facilities, offices, hospitals, and supermarkets. This study aims to evaluate IPS technologies' performance and applicability to guide practitioners in selecting systems suited to specific contexts. Methods: The study systematically reviews key IPS technologies, positioning methods, data types, filtering methods, and hybrid technologies, alongside real-world examples of IPS applications in various testing environments. Results: Our findings reveal that radio-based technologies, such as Radio Frequency Identification (RFID), Ultra-wideband (UWB), Wi-Fi, and Bluetooth (BLE), are the most commonly used, with UWB offering the highest accuracy in industrial settings. Geometric methods, particularly multilateration, proved to be the most effective for positioning and are supported by advanced filtering techniques like the Extended Kalman Filter and machine learning models such as Convolutional Neural Networks. Overall, hybrid approaches that integrate multiple technologies demonstrated enhanced accuracy and reliability, effectively mitigating environmental interferences and signal attenuation. Conclusions: The study provides valuable insights for logistics practitioners, emphasizing the importance of selecting IPS technologies suited to specific operational contexts, where precision and reliability are critical to operational success
Resizing the Workforce for Picking Activity: Application in the Fashion Sector
No full textOrder picking is one of the most critical activities in warehouses as being the most labor intensive with costs that can be up to 55% of total warehouse expenses. In this context the right sizing of picking workforce is decisive and has to guarantee a satisfactory service level. In this paper, workforce resizing for warehouse picking activities, was investigated in the light of the growth of receptivity required by one of the commissioning firms. Given the high labour intensity in the picking activities, the first phase of our analytical framework for the workforce resizing incl udes a statistical validation of the law of diminishing returns, which can be viewed as an effect of the free-rider behaviour, and then (i.e., second phase) a fitting approach of the said law; the curve that best fits the historical data is used in the third phase to forecast the future productivity. The last phase is made of an analytical procedure to derive the average future required number of ordinary and overtime pickers. We applied our framework in a real warehouse for a firm in the fashion sector, results highlighted a necessity for workforce increase, compared to the “as-is” scenario; this will allow the firm to strategically identify future workforce size requirements, from a cost-based perspective
Post-Occupancy Evaluation’s (POE) Applications for Improving Indoor Environment Quality (IEQ)
Full text linkTo improve buildings and their characteristics, the feedback provided directly by users is generally fundamental in order to be able to adapt the technical and structural functions to the well-being of users. The post-occupancy evaluation (POE) fits perfectly into this context. The POE, through qualitative and quantitative information on the interior environment, makes it possible to identify the differences between the performances modeled in the design phase and the real performances experienced by the occupants. This review of 234 articles, published between 2006 and 2022, aims to analyze and compare the recent literature on the application of the POE methodology. The aim was to provide both a qualitative and quantitative assessment of the main factors that comprise the indoor environmental quality (IEQ). The study highlighted the factors that comprise the quality of the indoor environment, as well as the variables that are usually analyzed to describe the well-being of the occupants. The results suggested which are the most common approaches in carrying out POE studies and will identify the factors that most influence the determination of the good quality of an indoor environment
Ergonomic risk assessment in lifting activities with Azure Kinect: an industrial case study
No full textWork related musculoskeletal disorders (WMDs) are common in industrial activities and their impacts on society are not negligible. To reduce them recently some motion capture technologies (MOCAP) are applied to semi automatically calculate the ergonomic risk to which operators are subjected. In this paper we present an industrial case study where an application based on a depth camera, the new Azure Kinect, is exploited to semi-automatically calculate the ergonomic risk involved in picking activities. The case study took place in a warehouse and regarded three different activities. The semi-automatic evaluation of the ergonomic risk highlighted some criticalities on how picking activities are carried out. For this reason, some modifications of the activities are proposed and tested revealing a statistically significant ergonomic risk reduction
How the type of customer can influence the product attributes: Application of house of quality with multi-user information to improve the functions of a waste collection and treatment service management software
No full textIndoor Positioning with Ultra-Wideband: Enhancing Accuracy through Data Filtering
No full textAbstract: Indoor positioning technology plays a vital role in tracking movements within spaces where traditional outdoor GPS systems fail to operate effectively. This research employed Ultra-Wideband (UWB) technology to monitor the live trajectory of operators within an actual production facility, highlighting the significance of warehouse re-layout. The system's effectiveness was assessed in two key zones: the goods receiving and shipping
area, and the space amidst warehouse shelves. Enhanced results were achieved through the implementation of various filtering techniques. Nonetheless, the study also uncovered practical limitations, revealing a level of accuracy lower than expected
On demand printing with Additive Manufacturing (AM) for spare parts: scenarios for the insourcing of a 3D Printer
No full textAdditive Manufacturing (AM) has become a promising technique for spare parts management. The reduced lead time of AM compared to Classical Manufacturing (CM) has attracted the interest of researchers and many applications of AM to spare parts management have been introduced in the literature. However, the high production and equipment costs obscure the advantages of AM to spare parts management to practitioners and academics. The recent literature on spare parts management with AM have two main limitations which we address in this work. The first is that AM spare parts are mistakenly assumed to be less reliable than CM ones, which has been refuted by the recent literature on the mechanical characteristics of AM parts. Secondly, the external supply of AM parts that excludes the investment cost of the equipment. Our model overcomes these limitations by taking into account a spare part installed on a fleet of systems which failures are based on failure data from recent literature. In addition, we consider an insourced 3D printer, and account for the purchasing cost. We propose several scenarios for the insourcing of a 3D printing, considering a future cost reduction and constrained stock systems, individuating constrained stock system with high lead times for the CM part, ideal for in-house printing. The work has been supported by the project SUPERCRAFT, funded by the Emilia-Romagna Region (Italy) with European funds (POR FESR)
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