Browsing by Author "Erkoyuncu, John ahmet"
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Item Open Access Cost uncertainty management and modelling for industrial product-service systems(Cranfield University, 2011-01) Erkoyuncu, John Ahmet; Roy, Rajkumar; Shehab, EssamGlobally manufacturing based industries are typically transforming operations to enhance the delivery of services throughout equipment use. Within the defence industry, Contracting for Availability (CfA) has emerged as an approach that is increasingly dominating the interation between the customer and the manufacturers. This application serves as an example for an Industrial Product-Service System, and sets the context to this research. Predicting the delivery of services, particularly at the bidding stage, creates enhanced complexity and unpredictability in costs due to uncertainties. Driven by this contextual challenge the aim of this research is to develop a framework for cost uncertainty management and modelling at the bidding stage of CfA in the defence industry. The thesis presents the existing literature associated to uncertainty in cost estimation, whilst the current practice is demonstrated based on interaction with seven organisations involved in the defence industry. A software prototype, Uncertainty Tool for Assessment and Simulation of Cost (U-TASC), has been developed to implement an integrated cost uncertainty management and modelling framework. The cost uncertainty management framework offers a systematic procedure at the bidding stage to guide subject matter experts to focus the attention on influential uncertainties, while also proposing suitable mitigation strategies. In contrast, the cost uncertainty modelling framework involves a step by step procedure to make use of subjective opinion collated from subject matter experts to reflect the influence of uncertainty in cost estimates. The thesis also presents an agent based model that takes into account the influence of dynamic uncertainty (e.g. failure rate) on cost estimates over time. This is applied within a service supply network, where the interaction between the stakeholders represents a typical CfA with incentives and risk sharing scenarios. The frameworks embedded in U-TASC are validated and verified through three case studies including, a naval radar, aircraft carrier, and naval electronic system. The outcomes indicate that reliable and useful results are generated and the tool is highly applicable. On the other hand, the framework for the agent based model is validated through expert opinion and a pilot case study in the naval domain.Item Open Access Datasets: Programmable content and a pattern-matching algorithm for automatic adaptive authoring in Augmented Reality for maintenance(Cranfield University, 2020-06-01 17:09) Fernández del amo blanco, Iñigo; Erkoyuncu, John ahmet; Farsi, MaryamThis repository includes datasets on experimental cases of study and analysis regarding the research called "Programmable content and a pattern-matching algorithm for automatic adaptive authoring in Augmented Reality for maintenance".DOI:Abstract: "Augmented Reality (AR) can increase efficiency and safety of maintenance operations, but costs of augmented content creation (authoring) are hindering its industrial deployment. A relevant research gap involves the ability of authoring solutions to automatically generate content for multiple operations. Hence, this paper offers programmable content formats and a pattern-matching algorithm for automatic adaptive authoring of ontology -based maintenance data. The proposed solution is validated against common authoring tools for repair and remote diagnosis AR applications in terms of operational efficiency gains achieved with the content they produce. Experimental results show that content from all authoring solutions attain same time reductions (42%) in comparison with non-AR information delivery tools. Surveys results suggest alike perceived usability of all authoring solutions and better content adaptiveness and user’s performance tracking of this authoring proposal."Item Open Access A design framework for technology prioritisation in the context of through-life engineering services(Elsevier, 2021-06-02) Chi, Jie; Latsou, Christina; Erkoyuncu, John Ahmet; Grenyer, Alex; Rushton, Keith R.; Brocklebank, SimonLack of methods on standardising the prioritisation of technologies within the context of Through-life Engineering Services (TES) has been identified. Inspired by the TES value streams and support activity assets, existing within a common TES framework, a new design framework for technologies prioritisation is proposed. A dynamic toolkit to identify the most suitable technology is also developed, using a Quality Function Deployment method, Analytic Hierarchy Process and ROI analysis. A real case study from the defence sector is employed to validate the developed design framework and toolkit; the results show a well-structured guide that can effectively simplify the decision-making process.Item Open Access Dynamics of cost uncertainty for innovative high value manufacturing products - a geometric phenomenon(Elsevier, 2018-11-24) Schwabe, Oliver; Shehab, Essam; Erkoyuncu, John AhmetIn practice the forecasting of cost uncertainty for high value manufacturing products is typically a statistical exercise focused on predicting a static cost range at a future point in time. This only leads to robust forecasts if sufficient historical data is available, robust knowledge of cost estimating relationships exists and these relationships do not change in the time between creating the forecast and verifying its accuracy. The more innovative the product is the less likely it however is that these prerequisites are met. Using cost data from the U.K. Ministry of Defence Royal Air Force A400M transport aircraft from 2002 to 2014 as an example, the dynamics of cost estimating relationships over time are examined using a novel non-statistical forecasting approach. The approach considers cost uncertainty as a geometric phenomenon, does not rely on prior information and permits easy identification of patterns in changes of cost estimating relationships over time.Item Open Access An effective uncertainty based framework for sustainable industrial product-service system transformation(Elsevier, 2018-09-22) Erkoyuncu, John Ahmet; Roy, Rajkumar; Shehab, Essam; Durugbo, Christopher; Khan, Samir; Datta, ParthaIndustrial Product-Service Systems (IPS2) can provide insights to enhance the environmental sustainability and lower environmental impact. However, its successful realisation for preventing the production of waste, while increasing efficiencies in the uses of energy and human capital remains a highly convoluted problem. This research article aims to address this issue by presenting an innovative uncertainty-based framework that can be used to assist in achieving increased sustainability within the context of IPS2. The developed framework explains the drivers for decision-making and cost to enable sustainability improvements in transforming to industrial services. This is based on academic literature, and multiple case studies of seven industrial companies with over 30 h of semi-structured interviews. The validation of the framework through two case studies demonstrates that uncertainty management can enable resource efficiency and offer sustainable transformation to service provision.Item Open Access A maturity model for rapid diffusion of innovation in high value manufacturing(Elsevier, 2021-02-10) Schwabe, Oliver; Bilge, Pinar; Hoessler, Andreas; Tunc, Taner; Gaspar, Daniel; Price, Nigel; Sharir, Lee; Pasher, Edna; Erkoyuncu, John Ahmet; de Almeida, Nuno Marques; Formica, Piero; Schneider, Lynne; Dietrich, Franz; Shehab, EssamIn order to support accelerating the diffusion of innovations in high value manufacturing related to enabling flexible mass customization, this paper presents a research-based maturity model for forecasting the speed of innovation diffusion from ideation to market saturation. The model provides an early stage applied research view of (groups of) “game changing” variables, which accelerate diffusion of innovations to significantly reduce financial uncertainty and minimize the time to derive value from the original idea. The model is applied to multiple case studies related to the repurposing and customization of existing mass manufacturing infrastructures and processes to meet novel requirements. Case studies include among others a reference model based on a literature review, the diffusion of 3-D printing technology in manufacturing, the diffusion of novel cement manufacturing technology and the manufacturing of intensive care ventilators during the Covid-19 pandemic. The diffusion of innovation model applied is based on diffusion of innovation principles founded in the research of Everett Rodgers, the Bass Diffusion Curve and aligned to recent advances in living (eco-) systems theory. Special emphasis is placed on determining not only the relevance of “known-known” success factors for rapid innovation diffusion, but also on identifying “unknown-unknown” game changers enabling the required changes at pace. Key findings are that “game changing” factors for the innovations are primarily the interdependent availability of budget and resources to achieve market saturation, urgency of need shared by all participants, observability of impact (value creation) and compatibility with existing ways of work. Critical as well is population of all diffusion web roles with unique individuals. Further research is suggested regarding the dependency of assessed variable (groups) and the integration of Technical Readiness Level phases into the forecasting model.Item Open Access Multistep prediction of dynamic uncertainty under limited data(Elsevier, 2022-01-12) Grenyer, Alex; Schwabe, Oliver; Erkoyuncu, John Ahmet; Zhao, YifanEngineering systems are growing in complexity, requiring increasingly intelligent and flexible methods to account for and predict uncertainties in service. This paper presents a framework for dynamic uncertainty prediction under limited data (UPLD). Spatial geometry is incorporated with LSTM networks to enable real-time multistep prediction of quantitative and qualitative uncertainty over time. Validation is achieved through two case studies. Results demonstrate robust prediction of trends in limited and dynamic uncertainty data with parallel determination of geometric symmetry at each time unit. Future work is recommended to explore alternative network architectures suited to limited data scenarios.Item Open Access A robust design for lifecycle cost with reliability analysis integration(Elsevier, 2023-07-08) Farsi, Maryam; Namoano, Bernadin; Sonmez, Ayse Nur; Addepalli, Pavan; Erkoyuncu, John AhmetMaintenance, repair, and overhaul (MRO) is the most significant cost driver over a complex engineering asset lifecycle. Therefore, high-value manufacturers are required to plan MRO occurrences to optimize the overhaul cost while achieving the desired performance. This trade-off imposes a shift towards a proactive maintenance strategy. However, creating a long-term proactive maintenance plan is challenging due to uncertainties in the performance of the asset and its critical components. Hence, this paper presents a robust design framework for the lifecycle cost estimation process by integrating reliability life data analysis. The level of data availability across the lifecycle is considered. The framework is proposed based on a literature review and the Delphi method. This study highlights that the level of robustness in the lifecycle cost estimates can be achieved by continuous feedback to the design phase and to the body of knowledge over the asset lifecycle. Moreover, this study suggests that the optimization model for the trade-off between cost and reliability should fulfil safety and environmental sustainability requirements when providing a cost-effective reliability solution.Item Open Access Toward an integrated sustainability assessment in through-life engineering services(Elsevier, 2020-10-26) Farsi, Maryam; Erkoyuncu, John AhmetThrough-life Engineering Services (TES) is comprised of develop, prepare, utilize and retire phases for complex engineering assets with a focus on maximizing their availability, predictability and reliability at the lowest possible life-cycle cost. TES employs a set of technologies and solutions to improve asset performance efficiently. On the other hand, optimal solutions for minimizing waste in terms of service time and resources is crucial for designing the right service at the right time. Thereby, specifying the possible TES opportunities within the economic, social and environmental sustainability dimensions can be an added value across different manufacturing sectors when deploying TES. However, due to the complexities and immensity of TES approaches, it is challenging to perceive such opportunities. To this end, the existing literature is limited to the effect of TES on economic sustainability and mostly focuses on investigating how TES has modified the service design to improve productivity and profitability. However, a comprehensive study on integrated sustainability has not been yet conducted. This paper presents a holistic view of the potential TES opportunities associated with the sustainability triple bottom line following a systematic review of empirical and theoretical advancements and methodological approaches in the literature. The outcome from this research raises the awareness of TES contribution in the design of sustainable service solutions and technologies, and offers a benchmark and reference point for future research in the field. Finally, this paper provides a set of recommendations that call for the further development of an integrated sustainability assessment framework for TES.