CERES :: Browsing by Author "Patsavellas, John"

Browsing by Author "Patsavellas, John"

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Open Access
A framework for enabling metaverse for sustainable manufacturing
(Elsevier, 2024) Assad, Fadi; Konstantinov, Sergey; Patsavellas, John; Salonitis, Konstantinos
Newly introduced technologies often require time for adoption and integration into manufacturing environments, for several reasons including technological maturity, adoption costs, and skills gaps. The inclusion of sustainability as a new requirement for both customers and producers adds further complexity to the equation. As metaverse technology became available, it became logical to establish a set of requirements to harness its new potential and create a sustainability-oriented framework for seamless integration into modern smart manufacturing environments. Against this background, the current work introduces a framework aimed at harnessing the potential of the metaverse to enhance manufacturing sustainability. As a case study, an industrial workshop was analysed and evaluated using the proposed framework. The findings help create a future plan for leveraging the use of the metaverse and prioritising its requirements.
Open Access
Automated assembly of Li-ion vehicle batteries: A feasibility study
(Elsevier, 2020-09-22) D’Souza, Ryan; Patsavellas, John; Salonitis, Konstantinos
Electric Vehicles (EVs) with rechargeable Lithium-Ion batteries (Li-ion) are at the forefront of the global trend for lower-emission transportation and decarbonisation. Capable suppliers of Li-Ion battery assembly systems are essential for enabling automotive OEMs to scale up their Li-ion EV production to expected volumes. This paper details a feasibility study for Li-Ion battery assembly, developed for a traditional automotive supplier of niche production systems in order to enable them to enter the emerging lower carbon OEM supply chains. Through simulation modelling, the essential components of a reconfigurable and scalable EV Li-ion batteries assembly system with provision for disassembly are explored and a generic framework is proposed.
Open Access
Business process re-engineering to digitalise quality control checks for reducing physical waste and resource use in a food company
(MDPI, 2021-11-09) Garcia-Garcia, Guillermo; Coulthard, Guy; Jagtap, Sandeep; Afy-Shararah, Mohamed; Patsavellas, John; Salonitis, Konstantinos
Quality control is an essential element of manufacturing operations that reduces product defects and provides excellent products of the right specifications to the end consumer. Industry 4.0 solutions, such as digitalisation, along with lean manufacturing tools, may support quality control operations. This paper presents a case study of a food company wherein quality control checks were optimised using business process re-engineering to reduce physical waste and resource usage. Following close analysis of the company’s pack-house operations, it was proposed to adopt elements of Industry 4.0 by digitalising the quality control process. Implementing such a solution led to a reduction in the time needed to complete recorded checks, an increase in the time the pack-house quality control team spends with packers on the production lines, and the facilitation of defects identification. It also ensured that the product met the customers’ specifications and reduced the likelihood of rejection at the customers’ depot. The new system also enabled monitoring of each line in real-time and gathering of additional information faster and more accurately. This article proves how employing lean principles in combination with Industry 4.0 technologies can lead to savings in resources and a reduction in waste, which leads to improvements in operational efficiency.
Open Access
Carbon accounting management in complex manufacturing supply chains: a structured framework approach
(Elsevier, 2022-05-26) Kaur, Rashmeet; Patsavellas, John; Haddad, Yousef; Salonitis, Konstantinos
Improving the management of carbon emissions in the drive to Net-Zero can involve both complex measurements and the development of cleaner technologies, which is a demanding challenge for both the private and public sectors. Specifically, within complex and often sensitive supply chains such as aerospace manufacturing, accounting for carbon management requires quantification of the extended enterprise’s direct and indirect emissions as a system. Currently however, there is a lack of standardised methods for carbon accounting suitable for use in the measurement and auditing of carbon performance both in the production process as well as in the supply chain. This research presents a structured framework-based approach, that could facilitate accurate, consistent and simplified management of carbon scoping, measurement and reporting, across complex extended supply chains. The proposed five step approach sets a thematic orientation for future customisation of carbon accounting tools at every step of the framework.
Open Access
The carbon footprint of manufacturing digitalization: Critical literature review and future research agenda
(Elsevier, 2019-06-24) Patsavellas, John; Salonitis, Konstantinos
As the world of manufacturing is accelerating to its digital paradigm, it could become a significant generator of energy-consuming data. The storage of such data is facilitated by the proliferation of easily accessible cloud services, whilst the cost of transmission and storage has significantly dropped. Within a sustainability context, the carbon-footprint characteristics of these masses of data-capture, transmission, storage and management have not been given adequate due-diligence. A cause of this omission may be the assumption that renewable forms of energy generation and storage, may eventually render the big cloud data-centers carbon neutral. However, such assumptions may be pre-mature and not synchronized with unfolding realities, as the carbon footprint implications of the industry 4.0 discourse have not been assessed. This paper ascertains the absence of any structured assessment framework of CO2 emissions of the various components of industrial digitalization, as an evaluation tool of the accelerating digital transformation of manufacturing within a sustainable growth context.
Open Access
Carbon nanotubes and graphene radiant heater printed on a cementitious flooring substrate: a feasibility study
(SSRN, 2020-10-26) Patsavellas, John; Salonitis, Konstantinos; Koziol, Krzysztof K. K.; Zakrzewski, Lukasz; Blackwood, Ben
The human activity of heating homes contributes a significant amount of CO2 in the total of the UK Green House Gases and the process of retrofitting residential stock and equipping new dwellings with lower and carbon neutral technologies could be complex, costly and physically challenging. This paper investigates the feasibility of a composite mixture of carbon nanotubes (CNT) and graphene material applied as a printed layer to the underside of a cementitious flooring substrate, acting as a radiant underfloor heater. Screening sample tests confirm instant radiant heating at low DC voltages with remarkably low conduction heat losses through the substrate.
Open Access
The concept of carbon accounting in manufacturing systems and supply chains
(MDPI, 2023-12-19) Kaur, Rashmeet; Patsavellas, John; Haddad, Yousef; Salonitis, Konstantinos
Carbon accounting is primarily a process for measuring, reporting, and allocating greenhouse gas emissions from human activities, thus enabling informed decision-making to mitigate climate change and foster responsible resource management. There is a noticeable upsurge in the academia regarding carbon accounting, which engenders complexity due to the heterogeneity of practices that fall under the purview of carbon accounting. Such plurality has given rise to a situation where diverse interpretations of carbon accounting coexist, often bereft of uniformity in definition and application. Consequently, organisations need a standardised, comprehensive, and sequentially delineated carbon accounting framework amenable to seamless integration into end-to-end manufacturing systems. This research commences with the progressive evolution of the conceptual definition of carbon accounting. Then, it delves into the current state of carbon accounting in manufacturing systems and supply chains, revealing gaps and implementation issues warranting future scholarly exploration.
Open Access
Critical success factors for improving learning management systems diffusion in KSA HEIs: an ISM approach
(Springer, 2021-07-07) Alduraywish, Yousef; Patsavellas, John; Salonitis, Konstantinos
Higher educational institutes (HEIs) are managing their resources by using learning management systems (LMS) which facilitate the learning processes. This paper aims to develop the relationships among success factors typically found in the technology, as well as the human and organisational aspects using an interpretive structural modelling (ISM) approach for LMS diffusion in HEIs in the Kingdom of Saudi Arabia (KSA). The success factors possessing a higher driving power in the ISM approach need to be prioritised as many other dependent variables are affected by them. Success factors emerging with high dependence contribute to facilitating the implementation of LMS. A key finding of the modelling is that clearly defined information technology (IT) policies along with appropriate technology infrastructure are significant factors for facilitating the technology aspect of LMS implementation. Additionally, the strengthening and standardisation of IT education resources, level of computer skills, proper training programmes for staff to deliver knowledge to users as well as a high level of human competencies are significant factors for facilitating the human aspect of LMS implementation. Moreover, the support of top management is a very significant factor for improving the organisational aspect of LMS. To ensure successful LMS implementation, KSA HEIs should focus on effective learning environments, facilitate education activities, top management involvement and increased interaction between pedagogy and technology. Understanding user characteristics and online needs is essential to ensure that barriers are overcome, ensuring successful and continued LMS implementation. Further, in this research, the relationship models among the identified success factors in terms of technology, human and organisational have not been statistically validated. However, it has been suggested that future research may be targeted to develop the initial model through ISM for success factors for improving LMS implementation and then testing it using Structural equation modeling (SEM).
Open Access
Enhancing sustainability in manufacturing through cognitive digital twins powered by generative artificial intelligence
(Elsevier, 2024-11) Assad, Fadi; Patsavellas, John; Salonitis, Konstantinos
The rise of Industry 4.0 has brought new advancements in manufacturing, with a focus on integrating digital technologies to optimise processes and increase sustainability. Cognitive Digital Twins (CDTs) are emerging as a powerful paradigm in this area. They leverage advanced analytics, artificial intelligence (AI), and machine learning to create dynamic, real-time representations of physical manufacturing systems. This paper explores how CDTs can improve sustainability within the manufacturing sector. It proposes integrating generative artificial intelligence (GenAI) into the platforms that operate these digital twins to grant them cognitive capabilities. The work introduces a method for mapping and integrating energy consumption data to an Internet of Things (IoT) platform that includes the digital twin and a generative AI language model, such as ChatGPT. This proposed approach serves as a stepping stone towards unlocking the full potential of CDTs. It empowers manufacturers to achieve higher levels of sustainability and environmental responsibility.
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Facilitating lean implementation through change management
(Elsevier, 2024) Al Manei, Mohammed; Kaur, Rashmeet; Patsavellas, John; Salonitis, Konstantinos
Implementing lean manufacturing can be challenging and requires all stakeholders to be engaged. Several frameworks have been presented in the last decades, with most of them being conceptual and failing to consider that change inertia exists. In the present paper, a social change management model is used to develop a lean implementation framework, with each step prescribed for the practitioners. The elements of the model are selected after a series of workshops, a thorough literature review, and the development of an interpretive structural model for this reason. The model was validated through experts’ opinions and presents an alternative approach to the established lean implementation roadmaps available in the literature.
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A framework for enhancing knowledge sharing through social media in higher education institutions in the KSA.
(Cranfield University, 2021-08) Alshalaan, Mohamed Nasser R.; Salonitis, Konstantinos; Patsavellas, John
Social media tools have changed the way individuals and academics impart, share content, inter-face, and team up. These days, social media is turning into an important stage for encouraging knowledge sharing and correspondence. The current research focuses on a framework for enhancing of the use of social media for knowledge sharing in higher education institutes (HEIs) in the Kingdom of Saudi Arabia (KSA) by using knowledge-sharing models and theories. The proposed framework was validated in the KSA academic sector. This research used semi-structured interviews with 31 participants from various departments in HEIs. The quantitative data were analysed using descriptive and inferential statistics. The qualitative data were analysed using a thematic analysis approach. The research identifies the factors influencing knowledge sharing through social media based on three aspects: individual, organisational, and technological dimensions. The contribution of this research includes a new framework derived from previous models and theories to investigate the potential factors that influence the use of social media for knowledge sharing. The interpretive structural models were applied based on the factors from the literature review and the findings from interviews. The findings lead to the development of a framework for the development of the knowledge- sharing process through social media in KSA HEIs. The proposed framework was validated using experts’ feedback. An interpretive structural model (ISM) as presented for a better understanding of the relationships among the critical factors. The ISM model contributed to the development framework of knowledge-sharing factors through social media. The proposed framework has the ability to identify potential factors and improve the knowledge-sharing process through social media. This research will help educational institutions to know how to support the use of social media tools for knowledge-sharing purposes by focusing on critical factors.
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A framework for the development of learning management systems for higher education institutions in the Kingdom of Saudi Arabia
(Cranfield University, 2020-08) Alduraywish, Yousef Ahmed Y; Salonitis, Konstantinos; Patsavellas, John
This study focuses on a framework for the development of the Learning Management System (LMS) in the Kingdom of Saudi Arabia (KSA) higher education institutes (HEIs) from information systems (IS) perspective, using the Technology Acceptance Model (TAM) and Design Reality Gap (ITPOSMO) model. The research methodology consists of six stages which adopts the paradigm of pragmatism and the research design of mixed-methods. A case study design is used to investigate the implementation of LMS in the Al-Imam Mohamed bin Saud Islamic University. The quantitative part was designed to investigate the attitude of users towards the usefulness of the LMS and to assess the acceptance level of LMS among university users. The qualitative part was designed to explore the gap between the proposed implementation of the LMS and reality. The survey received valid responses from 129 academic and 1548 student. A semistructured interviews with 21 participants. The sample was achieved via a purposive sampling technique. The quantitative data was analysed using descriptive statistical analysis and correlation coefficient. The qualitative data were analysed using a thematic analysis approach. The study identifies the barriers influencing effective LMS in KSA HEIs as 1) technology barriers (lack of IT infrastructure, incomplete functionalities and lack of integration); 2) human barriers (lack of knowledge of the importance of elearning, lack of expertise and competencies); and 3) organisation barriers (organisational preparedness, unclear of requirements, lack of training, resistance and financial constraints). The contribution of this research includes a new model derived from the ITPOSMO model and TAM to investigate LMS in the context of real circumstances, and the physical environment that exists in KSA HEIs. The research focus is more on meso level while encompassing first and third levels as reference for better understanding (Richter et al., 2009). The results lead to developing a framework for the development of LMS in KSA HEIs.
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Improving the curing cycle time through the numerical modeling of air flow in industrial continuous convection ovens
(Elsevier, 2017-07-11) Yi, Yuan; Salonitis, Konstantinos; Tsoutsanis, Panagiotis; Litos, Lampros; Patsavellas, John
Drying, curing, baking are few of the manufacturing processes that require the use of impingement ovens. For the manufacturing of large batches typically continuous flow ovens are used that are part of an automated conveyor processing line. The retention time for a product to be treated in the oven usually drives the production efficiencies (i.e. energy usage or lead times). In many processing lines though, the ovens are not designed and run in the most efficient way, and as a result become the “bottleneck” process phase. In such ovens, usually the hot air is ejected from rows of nozzles perpendicularly to the moving product. In the most advanced designs the ovens are divided in zones, with each zone having different targeted operating temperature. The optimization of the manufacturing process is difficult to be experimentally determined due to several reasons: the length of the ovens and the complexity of the movement of the product in and out of the oven are the most challenging ones. The main objective of this paper thus is the development of a Computer Fluid Dynamics model for simulating the thermal - transfer efficiency of an existing hot-air convection oven used to produce continuous products. The model is used for the estimation of the maximum speed that the conveyor belt can be run, and further investigate possible improvements on the design of the oven for the reduction of the cycle time. The results can be useful during the overview of the actual production and manufacturing rules.
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An investigation between the links of sustainable manufacturing practices and innovation
(Elsevier, 2023-04-18) Litos, Lampros; Patsavellas, John; Afy-Shararah, Mohamed; Salonitis, Konstantinos
Without a clear sustainability agenda in place, manufacturing companies would typically aim for products with incremental improved performance for their customers or introducing novel and innovative products and services that appeal to their target audience. However, mounting pressures to improve environmental performance indicators (carbon emissions, waste) require companies to think about step change improvements in how they operate and manage energy and resources. Companies trying to make their products with less energy and materials (doing more with less) are likely to face, or must address, operational and systemic changes in order to achieve better outcomes for the environment or ESG targets. Part of the issue at hand is the complexity and effort required to design effective changes with positive environmental outcomes and minimal disruption for on-going operations and manufacturing performance. In this article the authors aim to extend and explore the utility of a novel maturity model for eco-efficiency into innovation processes and practices and better understand the implications for theory and practice.
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Management tool design for eco-efficiency improvements in manufacturing - a case study
(Elsevier, 2017-05-09) Litos, Lampros; Borzillo, Fiammetta; Patsavellas, John; Cockhead, David; Salonitis, Konstantinos
As the worldwide GDP is forecasted to double by 2035, the energy demand globally is expected to increase by 34%. The industrial sector is also expected to account for more than 30% of the primary energy demand by 2040. These projections make manufacturing operations even more complicated when combined with predicted long-term inflation of raw material prices and increasingly stringent environmental regulations. Therefore, it has become increasingly more challenging for practitioners in manufacturing to improve their eco-efficiency or to “do more with less”. Traditional manufacturing management tools based on lean principles such as Value Stream Mapping have not been designed to facilitate eco-efficiency improvements. On the other hand, environmental management tools such as Life-Cycle Analysis focus more on improving environmental impacts rather than financial sustainability. This paper addresses the design gap between these tools and proposes an integrated toolkit for eco-efficiency improvements. The toolkit development process and design principles are described through a case study in the flooring industry. Results from each module are validated and the overall output is used to propose a range of applicable solutions to the manufacturer. Paper presented at: Complex Systems Engineering and Development Proceedings of the 27th CIRP Design Conference Cranfield University, UK 10th – 12th May 2017.
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Manufacturing in the time of COVID-19: an assessment of barriers and enablers
(IEEE, 2020-07-27) Okorie, Okechukwu; Subramoniam, Ramesh; Charnley, Fiona; Widdifield, David; Patsavellas, John; Salonitis, Konstantinos
Pandemics and other forms of epidemic outbreaks are a unique case of manufacturing risk typified by high uncertainty, increasing propagation and long-term disruption to manufacturers, supply chain actors as well as the end-users and consumers. For manufacturing the COVID-19 disruption scope has been largely two-fold; an endogenous disruption of manufacturing processes and systems as well as extreme shifts in demand and supply caused by exogenous supply chain disruption. Existing literature on disruptions in manufacturing suggests that pandemics are qualitatively different from typical disruptions. There is no literature available to manufacturing practitioners that identify the barriers and enablers of manufacturing resilience, especially with regards to pivoting of the manufacturing sector in response to a pandemic. This study draws on an extensive survey collected during the COVID-19 pandemic. The respondents were employees of manufacturing firms in all regions of the world who had engaged in manufacturing during the pandemic or had opted out from manufacturing due to various identified reasons. By collating their responses, we offer to practitioners and policymakers an analysis for identifying a best-practice framework for pivoting successfully as a response to major manufacturing disruptions.
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Modelling sources of operational noise in production systems
(Elsevier, 2021-07-30) Afy-Shararah, Mohamed; Patsavellas, John; Salonitis, Konstantinos
This paper aims to identify and model the sources of operational noise that contribute to unstable and poor flow of materials in production systems. 80 interviews with managers and decision-makers were conducted and analyzed and have revealed that internal technical instabilities, employee variability, and customer and supplier uncertainty are the major sources of operational noise. They have also identified the relationships between the different variables of a production system that contribute to the amplification of operational noise and hence should be managed effectively to ensure a smooth flow in manufacturing operations.
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Modelling the operations of a circular economy fashion start-up
(Elsevier, 2024-01-12) de Olañeta, Javier; Patsavellas, John; Salonitis, Konstantinos
This paper presents a case study of Pantala, a fashion start-up, intending to operationalise a circular supply of luxury womenswear through a monthly subscription-fee model. To optimize the company's cashflow and ensure success, the operational flows were modelled and analysed through discrete-event simulation techniques, with a focus on inventory management and minimizing operational costs. Simulation results demonstrated a high level of accuracy in predicting system performance, with an average relative error of less than 5% for most performance indicators. Insights are provided into the benefits of using simulation modelling for operational planning and optimization of complex systems, especially in the case of start-ups.
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Multi-objective reconfigurable manufacturing system scheduling optimisation: a deep reinforcement learning approach
(Elsevier, 2023-11-22) Tang, Jiecheng; Haddad, Yousef; Patsavellas, John; Salonitis, Konstantinos
Rapid product design updates, unstable supply chains, and erratic demand phenomena are challenging current production modes. Reconfigurable manufacturing systems (RMS) aim to provide a cost-effective solution for responding to these challenges. However, given their complex adjustable nature, RMSs cannot fully unlock their potential by applying old-fashion fixed dispatching rules. Reinforcement learning (RL) algorithms offer a useful approach for finding optimal solutions in such complex systems. This paper presents a framework to train a scheduling agent based on a proximal policy optimisation (PPO) algorithm. The results of a numerical case study that implemented the framework on a simplified RMS model, suggest a good level of robustness and reveal areas of unpredictable behaviour that could be the focus of further research.
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Printed carbon nanotube and graphene heaters for drying ceramics
(Springer, 2023-02-11) Sherif, Ziyad; Patsavellas, John; Salonitis, Konstantinos
The ceramic manufacturing process has been subject to many advances with the evolution of new technologies. However, there are still some delays and losses in the fundamental process which may be mitigated by deploying alternative technical tools and methods. One such stage is the sensitive pre-drying phase in which ceramic bodies can sustain drying defects such as micro-cracking and fractures due to lack of fine process control. This project investigates the feasibility of using Longwave infrared (LWIR) radiation emitted by a printed Carbon Nanotubes and Graphene (CNTG) heater for pre-drying a clay sample. The CNTG heater emits infrared radiation with a relatively low DC voltage power supply. By radiant heat transfer, homogeneous and uniform drying has been observed in the sample. The penetrative capability of the infrared energy which warms the inside of the sample is presented, as along with the results of comparing the CNTG heater with a silicone mat heater that also emits infrared radiation. The study establishes that the CNTG heater is not only capable of reducing the lead time of ceramics drying using penetrative IR, but also as an efficient and versatile option that can be economically deployed in the pre-drying stage of a ceramic manufacturing process.