Browsing by Author "Salonitis, Konstantinos"
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Item Open Access Analysis of lean manufacturing strategy using system dynamics modelling of a business model(Emerald, 2019-08-22) Gomez Segura, Miguel; Oleghe, Omogbai; Salonitis, KonstantinosA system dynamics-based methodology is described for analysing the impact of lean manufacturing strategies on a company's business performance, using Business Model Canvas perspective. A case study approach is used to describe the methodology which consists of conceptualizing a system dynamics model on the basis of Business Model Canvas. The base system dynamics model is elaborated to include variables and concepts that consider the effects of lean manufacturing metrics on business performance. In the modelling experimentation, the lean manufacturing metrics are made to take on likely values one would expect if certain lean practices are initiated or improved. The experimental results provide one with the likely impact on business performance, if one were to improve lean manufacturing practices. The simulation results for the case study show that lean improvements, on the short-run, have a significant impact on business performance, but on the long-run, the impact is only marginal. The described methodology provides one with a structured format for investigating the impact of lean practices on business performance. Although the developed system dynamics model was built with generality in mind, it remains to be reproduced in other settings to test its replicability. The methodology enables an organization target which lean improvements to initiate based on their strategic impact on the business. Limited studies exist where system dynamics and business models are combined to test the strategic impact of lean manufacturing.Item Open Access Analysis of the evolution of aerospace manufacturing ecosystems(Cranfield University, 2020-06) Luna Andrade, Jose Junior; Salonitis, Konstantinos; Brintrup, AlexandraThe aerospace manufacturing industry is predicted to continue growing. Understanding its evolution is thus essential to prepare optimal conditions to nurture its growth. This research aims to help the growth of emerging aerospace ecosystems by identifying evolution patterns and categorising key enablers that have encouraged the growth of developed ones. The term aerospace ecosystem is used to embrace all the business activities and infrastructure that are related to the entire aerospace’s supply chain in a specific country. Inspired by studies that have successfully combined economics and network science, in this research, bipartite country-product networks are developed based on trade data over 25 years. The United Kingdom (UK), the United States of America, France, Germany, Canada and Brazil’s are first analysed as evidence suggests that their aerospace ecosystems are within the most developed in the world. Then, China and Mexico’s networks are analysed and compared with developed ones, as these countries have evidenced emergent aerospace ecosystems. Results reveal that developed ecosystems tend to become more analogous, as countries lean towards having a revealed comparative advantage (RCA) in the same group of products. Further analysis shows that manufactured products have a stronger correlation to an aerospace ecosystem than primary products; and in particular, the automotive sector shows the highest correlation with positive aerospace sector evolution. Key enablers related to the growth of the UK and Mexico’s aerospace ecosystems are identified and categorised using interpretive structural modelling (ISM) and cross-impact matrix multiplication applied to classification (MICMAC) methodologies. Results evidence relevant differences in the categorisation of key enablers among a developed and emergent aerospace ecosystems. On the other hand, it was identified that geopolitical factors and the automotive ecosystem are underpinning enablers for both aerospace ecosystem’s evolution. The final aim is that results of this research could be implemented on emerging aerospace ecosystems by emulating the patterns and key enablers that have characterised the evolution of developed aerospace ecosystems.Item Open Access An approach to airline MRO operators planning and scheduling during aircraft line maintenance checks using discrete event simulation(Elsevier, 2021-07-30) Albakkoush, Salah; Pagone, Emanuele; Salonitis, KonstantinosThe process of scheduling and planning refers to examining aircraft history based on when and where the aircraft should go for service checks. In this paper, the authors focused on line maintenance activities and examined the impact of unexpected factors (Missing tools and safety requirements) on such activities during the process through a Discrete Event Simulation (DES) model. The DES was used to determine the following: 1. The plan time of each maintenance task according to maintenance scheduling based on the X airline company in Libya; 2. A tasks and productivity evaluation which involved examining the number of tasks required to do per check according to the scheduling plan and planned tasks performed by technicians, and; 3. The total elapsed time involved by analysing the average time for each task according to maintenance schedule planning. The results show that, for all scenarios conducted, the DES model was operating at a high level, and in some scenarios, there was a breakdown in service tasks; a clear indication that the workload factor was high during check periods. However, the main finding in this study highlights how a number of different tasks or the breakdown of maintenance work packages were not being completed before the actual time that had been allocated for the general external condition A-check of the aircraft. This made it necessary to study the work package for each check separately and examine these work packages as they relate to DES which presents a potential solution to a more efficient planning approach. This feature enhances the applicability of the proposed method in real-life, and helps airlines cope with the dynamic environment of airline MRO.Item Open Access Approach to value stream mapping for make-to-order manufacturing(Elsevier, 2020-09-22) Mudgal, Devanshu; Pagone, Emanuele; Salonitis, KonstantinosThis paper presents a new approach to the Value Stream Mapping (VSM), a proven tool of Lean Manufacturing (LM) in a Make-To-Order (MTO) manufacturing environment. The use of VSM in mass production has proven to be successful due to the predictable volume and repetitive product type. Within a MTO environment the product is tailored to specific requirements and varying volumes make it hard to balance production causing lean waste. The approach combines the classic VSM technique with commonality analysis to get a better understanding of the processes. Author illustrates this approach using a case study. Using VSM for MTO requires some changes to capture the attributes of product families required at different frequencies and volumes successfullyItem Open Access An assessment of environmental related key performance indicators of the chemical industries(IOS Press, 2022-09-08) Alfarsi, Alaa; Jagtap, Sandeep; Salonitis, KonstantinosOne of the most critical issues faced by chemical industries is reducing the environmental impact caused due to pollution, which has resulted in global warming and health issues. Most chemical industries monitor and use Key Performance Indicators (KPIs) to control pollution, which is currently done by using various KPI’s that are dependent on the product they are producing. Therefore, a study is conducted using a systematic literature review (SLR) focused on articles published between 2000 and 2022 to identify and categorize various KPIs that manufacturers have used to reduce their respective pollution. The results were divided into four main categories – air, water, land, and other pollution. The results demonstrated that ethylene manufacturing industries are the major contributor to air pollution. The mining, gas, and oil industries significantly resulted in water pollution. The land and groundwater pollution were mainly due to mining industries. The other pollution was mainly due to activities such as maintenance and performance of equipment and quality of raw materials.Item Open Access Automated assembly of Li-ion vehicle batteries: A feasibility study(Elsevier, 2020-09-22) D’Souza, Ryan; Patsavellas, John; Salonitis, KonstantinosElectric 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.Item Open Access Automatically weighted high-resolution mapping of multi-criteria decision analysis for sustainable manufacturing systems(Elsevier, 2020-02-01) Pagone, Emanuele; Salonitis, Konstantinos; Jolly, Mark R.A common feature of Multi-Criteria Decision Analysis (MCDA) to evaluate sustainable manufacturing is the participation (to various extents) of Decision Makers (DMs) or experts (e.g. to define the importance, or “weight”, of each criterion). This is an undesirable requirement that can be time consuming and complex, but it can also lead to disagreement between multiple DMs. Another drawback of typical MCDA methods is the limited scope of weight sensitivity analyses that are usually performed for one criterion at the time or on an arbitrary basis, struggling to show the “big picture” of the decision making space that can be complex in many real-world cases. This work removes all the mentioned shortcomings implementing automatic weighting through an ordinal combinatorial ranking of criteria objectively set by four pre-defined weight distributions. Such solution provides the DM not only with a fast, rational and systematic method, but also with a broader and more accurate insight into the decision making space considered. Additionally, the entropy of information in the criteria can be used to adjust the weights and emphasise the differences between potentially close alternativeItem Open Access Benchmarking of energy consumption and CO2 emissions in cement production: a case study(Springer, 2024-02-02) Sarfraz, Shoaib; Sherif, Ziyad; Jolly, Mark; Salonitis, KonstantinosIn the pursuit of economic growth and value creation, foundation industries including cement, metals, glass, chemicals, paper, and ceramics face formidable challenges related to energy usage, emissions, and resource consumption in their manufacturing operations, all while striving to achieve ambitious Net Zero carbon and green targets. To overcome these challenges and propel sustainable progress, benchmarking emerges as a powerful ally. This study performs a benchmarking analysis of energy use and CO2 emissions for a UK cement plant as well as best available techniques (BAT) investigation to identify opportunities for performance improvement in crucial areas such as energy usage and environmental sustainability. The research utilises industrial data from a 2850 tonne per day capacity dry process cement plant. Key energy and emissions parameters, including thermal and electrical energy intensity, recovered energy and CO2 intensity, are computed per tonne of cement produced along with capacity utilisation across major process stages including raw material grinding, clinkerisation, and cement grinding. Comprehensive data sourced directly from the manufacturer is compared against literature benchmarks for global averages and best practices. Although surpassing global average values, the plant lags European best practices across all metrics, signalling room for substantial improvement. Assessment of relevant BATs for the cement industry reveals prospects to integrate vertical roller mills for cement grinding and use Organic Rankine Cycle (ORC) at the clinkerisation stage. Adopting these techniques could reduce the electrical energy intensity of clinkerisation by 51% and cement grinding electrical intensity by 30%, surpassing benchmarks. While limited to a single cement plant, the study provides a standardised methodology that could be replicated across foundation industries to enable performance tracking and highlight efficiency gaps. The benchmarking approach developed can guide the implementation of energy conservation measures and the adoption of best practices by the cement industry to reduce its carbon footprint.Item Open Access Carbon footprint comparison of bitcoin and conventional currencies in a life cycle analysis perspective(Elsevier, 2023-04-18) Pagone, Emanuele; Hart, Alexandre; Salonitis, KonstantinosCryptocurrencies are a digital form of money based on the blockchain technology. Their relatively recent raise in popularity and use, together with the energy-intensive nature of some of their algorithms, has raised environmental concerns about growing energy consumption (and associated carbon dioxide emissions). This paper aims at comparing the environmental impact of the most common cryptocurrency (i.e., Bitcoin) and fiat currencies (i.e. coins, banknotes, credit and debit card networks). Such comparison is carried out assessing and analyzing the life cycle main phases of each currency in terms of carbon dioxide equivalent emissions. Results show that Bitcoin has a carbon footprint almost 4 to 5 times greater than the sum of all forms of traditional currency together in one year. Furthermore, environmental impact “hotspots” of fiat currency including raw material production of coins, transportation of banknotes and electric energy consumption of ATMs are identified. Finally, considering future scenarios and the sensitivity of various parameters on the results, some solutions are proposed to reduce the environmental impact of currencies.Item 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, BenThe 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.Item Open Access Ceramic matrix composites for aero engine applications - a review(MDPI, 2023-02-26) Karadimas, George; Salonitis, KonstantinosCeramic matrix materials have attracted great attention from researchers and industry due to their material properties. When used in engineering systems, and especially in aero-engine applications, they can result in reduced weight, higher temperature capability, and/or reduced cooling needs, each of which increases efficiency. This is where high-temperature ceramics have made considerable progress, and ceramic matrix composites (CMCs) are in the foreground. CMCs are classified into non-oxide and oxide-based ones. Both families have material types that have a high potential for use in high-temperature propulsion applications. The oxide materials discussed will focus on alumina and aluminosilicate/mullite base material families, whereas for non-oxides, carbon, silicon carbide, titanium carbide, and tungsten carbide CMC material families will be discussed and analyzed. Typical oxide-based ones are composed of an oxide fiber and oxide matrix (Ox-Ox). Some of the most common oxide subcategories are alumina, beryllia, ceria, and zirconia ceramics. On the other hand, the largest number of non-oxides are technical ceramics that are classified as inorganic, non-metallic materials. The most well-known non-oxide subcategories are carbides, borides, nitrides, and silicides. These matrix composites are used, for example, in combustion liners of gas turbine engines and exhaust nozzles. Until now, a thorough study on the available oxide and non-oxide-based CMCs for such applications has not been presented. This paper will focus on assessing a literature survey of the available oxide and non-oxide ceramic matrix composite materials in terms of mechanical and thermal properties, as well as the classification and fabrication methods of those CMCs. The available manufacturing and fabrication processes are reviewed and compared. Finally, the paper presents a research and development roadmap for increasing the maturity of these materials allowing for the wider adoption of aero-engine applications.Item Open Access The challenges for energy efficient casting processes(Elsevier, 2016-02-19) Salonitis, Konstantinos; Zeng, Binxu; Mehrabi, Hamid Ahmad; Jolly, Mark R.Casting is one of the oldest, most challenging and energy intensive manufacturing processes. A typical modern casting process contains six different stages, which are classified as melting, alloying, moulding, pouring, solidification and finishing respectively. At each stage, high level and precision of process control is required. The energy efficiency of casting process can be improved by using novel alterations, such as the Constrained Rapid Induction Melting Single Shot Up-casting process. Within the present study the energy consumption of casting processes is analyzed and areas were great savings can be achieved are discussed. Lean thinking is used to identify waste and to analyse the energy saving potential for casting industry.Item Embargo Challenges to Lean 4.0 in the pharma supply chain sustainability(Springer, 2023-08-25) Tetteh, Michelle Grace; Jagtap, Sandeep; Gupta, Sumit; Raut, Rakesh; Salonitis, KonstantinosThe Pharma sector is increasingly under pressure to improve the sustainability of supply chains, as consumers and regulators require greater transparency, efficiency, and accountability. Although Lean 4.0 has created a lot of buzz in the organization, the pharmaceutical sector faces challenges in implementing it. The main goal of this literature review is to identify the challenges of Lean 4.0 for the sustainability of the pharma supply chains (PSCs). A series of papers extracted from the most relevant scientific databases, including the Web of Science, Scopus, Google Scholar, and ProQuest was analyzed and synthesized from 2007 to 2022. 31 articles were used in the study. The findings of the study indicate that challenges include financial, staff experience and specialization, ongoing maintenance, resources for generating new skills and experiences, employees, and partners’ resistance to changes in regulations, and cyber-hacking of key information. The results will facilitate future work by practitioners and researchers and make an important contribution to existing knowledge.Item Open Access Characterising flow with continuous aeration in an oscillatory baffle flow reactor using residence time distribution(Royal Society of Chemistry, 2023-08-30) Cox, Rylan; Salonitis, Konstantinos; Impey, Susan A.; Rebrov, EvgenyMulti-phase flow occurs in many reactions with gas, an integral part of the reaction. This study assesses the synergistic impact of continuous aeration and velocity ratio on mixing conditions within an oscillatory baffled flow reactor to enhance the degree of plug flow, quantified by a tanks-in-series (TiS) model. A bubbly flow regime is shown in all experiments. In most cases, the TiS value was reduced with gas flow, and a maximum TiS value of 23.6 was achieved at a velocity ratio of 3.8 at 225 ml min−1 in a counter-current direction. Single-phase runs and co-current multi-phase runs produced maximum TiS values of 23.5 and 18.2 respectively at a velocity ratio of 2.2. Regardless of the gas flow rate, the velocity ratio was found to be the most influential factor that dictates the level of plug flow within the OBR. A predictive model is developed and used to maximise the mixing efficiency by determining the level of plug flow within the OBR at selected amplitudes, frequencies, and gas flow rates.Item Open Access A CNC machine guiderail wear in-process monitoring system(Cranfield University, 2016-09) Zhao, Yifei; Mehnen, Jorn; Salonitis, KonstantinosThis research investigates and establishes a system for monitoring the guiderail wear on medium size CNC machines. The system possesses the function of measuring the wear state on guiderails in an in-process way, which is more functional and efficient than the traditional method. In this research, two different types of sensors for monitoring each particular friction wear feature have been implemented. Calculations to complete designing of a physical experimental rig and the realisation of in-process monitoring are also discussed in detail. The first type sensor adopted in the experiment is the accelerometer, used for monitoring the vibration caused by the wear on bearings and the increasing roughness on the guiderail surface. The second sensor is the capacitance probe mounted on the table and against a straight edge, searching the deviation signal of the moving table while rolling on the guiderail surface with wear. The novelty of this thesis covering an in-process monitoring approach has been tested based on a physical experimental rig. The data calculation illustrates how the noise and other disturbances are filtered and data analysed to determine the state of wear. This system utilises an indirect solution to wear monitoring with less cost while delivering convincing reliability according to the experiment result. The thesis shows the possibility to acquire CNC machine guiderail wear data through an in-process monitoring system.Item Open Access Comparative life cycle assessment of aluminium and CFRP composites: the case of aerospace manufacturing(Springer, 2024-02-24) Atescan-Yuksek, Yagmur; Mills, Andrew; Ayre, David; Koziol, Krzysztof K. K.; Salonitis, KonstantinosAs climate change intensifies and existing resources are depleted, the need for sustainable industries becomes more important. The aviation industry is actively addressing environmental concerns by enhancing fuel efficiency and adopting lighter materials, especially carbon fibre composites. Research has proven that the use of carbon fibre composites provides cumulative benefits in reducing fuel consumption over the entire life cycle of an aircraft. However, existing studies are lack of a comprehensive exploration of the diverse impacts associated with composite manufacturing processes and recycling methods. To address this gap, a comparative life cycle assessment analysis covering the materials’ manufacturing, operation, and end-of-life phases is conducted. This analysis includes aluminium alloy and five different carbon fibre composite materials produced with varied constituents and manufacturing methods. Composite manufacturing processes, encompassing carbon fibre production, resin selection, and composite manufacturing methods, are considered. Weight savings based on the mechanical properties of utilised composite type are also taken into account. Results highlight the potential to mitigate the environmental impact of composite materials through strategic choices in constituent types, manufacturing processes, and disposal scenarios. Moreover, break-even distances indicate that aluminium becomes more environmentally detrimental than the analysed composite structures beyond a flight distance of 300,000 km.Item Open Access Comparative study of multi-criteria decision analysis methods in environmental sustainability(KES International, 2022-09-16) Pagone, Emanuele; Salonitis, KonstantinosMulti-Criteria Decision Analysis (MCDA) is an operations research framework used to support decision-makers in choosing alternatives characterized by multiple conflicting criteria. Over the past years, several MCDA methods have been developed and a significant drawback of using more than one algorithm for a given problem is the potential conflicting ranking that they may yield. This work aims at setting the first steps toward a systematic framework that reconciles different rankings from MCDA methods and returns to the decision maker a unique solution. The proposed method is contextualised within the existing scientific literature and illustrated considering four case studies to select environmentally sustainable solutions. Results show that a ranking agreed by multiple MCDA methods is more reliable than a ranking obtained by one method.Item Open Access A comparative study of multiple-criteria decision-making methods under stochastic inputs(MDPI, 2016-07-21) Kolios, Athanasios; Mytilinou, Varvara; Lozano Minguez, Estivaliz; Salonitis, KonstantinosThis paper presents an application and extension of multiple-criteria decision-making (MCDM) methods to account for stochastic input variables. More in particular, a comparative study is carried out among well-known and widely-applied methods in MCDM, when applied to the reference problem of the selection of wind turbine support structures for a given deployment location. Along with data from industrial experts, six deterministic MCDM methods are studied, so as to determine the best alternative among the available options, assessed against selected criteria with a view toward assigning confidence levels to each option. Following an overview of the literature around MCDM problems, the best practice implementation of each method is presented aiming to assist stakeholders and decision-makers to support decisions in real-world applications, where many and often conflicting criteria are present within uncertain environments. The outcomes of this research highlight that more sophisticated methods, such as technique for the order of preference by similarity to the ideal solution (TOPSIS) and Preference Ranking Organization method for enrichment evaluation (PROMETHEE), better predict the optimum design alternative.Item Open Access Comparative study of structural reliability assessment methods for offshore wind turbine jacket support structures(MDPI, 2020-01-26) Shittu, Abdulhakim Adeoye; Mehmanparast, Ali; Wang, Lin; Salonitis, Konstantinos; Kolios, AthanasiosOffshore wind turbines (OWTs) are deployed in harsh environments often characterized by highly stochastic loads and resistance properties, thus necessitating the need for structural reliability assessment (SRA) to account for such uncertainties systematically. In this work, the SRA of an OWT jacket-type support structure is conducted, applying two stochastic methods to predict the safety level of the structure considering various design constraints. The first method refers to a commercial finite element analysis (FEA) package (DesignXplorer© from ANSYS) which employs direct simulations and the six sigma analysis function applying Latin hypercube sampling (LHS) to predict the probability of failure. The second method develops a non-intrusive formulation which maps the response of the structure through a finite number of simulations to develop a response surface, and then employs first-order reliability methods (FORM) to evaluate the reliability index and, subsequently, the probability of failure. In this analysis, five design constraints were considered: stress, fatigue, deformation, buckling, and vibration. The two methods were applied to a baseline 10-MW OWT jacket-type support structure to identify critical components. The results revealed that, for the inherent stochastic conditions, the structural components can safely withstand such conditions, as the reliability index values were found acceptable when compared with allowable values from design standards. The reliability assessment results revealed that the fatigue performance is the design-driving criterion for structural components of OWT support structures. While there was good agreement in the safety index values predicted by both methods, a limitation of the direct simulation method is in its requirement for a prohibitively large number of simulations to estimate the very low probabilities of failure in the deformation and buckling constraint cases. This limitation can be overcome through the non-intrusive formulation presented in this work.Item Open Access Comparison of the environmental impact of the CRIMSON process with normal sand casting process(2013-09-02T00:00:00Z) Zeng, Binxu; Salonitis, Konstantinos; Jolly, Mark R.; Shehab, Essam; Ball, Peter D.; Tjahjono, BennyThe CRIMSON process is an alternative process to conventional casting that can be used for small to medium batch sizes. The aim of this process are to improve the casting quality and reduce the energy consumption within light-metal casting industry. Nowadays, the energy efficiency becomes more and more important. This is not only about the cost of the production, but also about the environmental effect. In this paper, the CRIMSON process will be compared with the conventional sand casting process. The Life cycle assessment (LCA) method will be used to assess the environmental impact of both casting processes.