Product Service System Concept Research Articles

Investigating social and environmental hotspots throughout the lifecycle of product-service systems in the early design stages

Product-Service Systems (PSS) have been recognized as potential game-changers for advancing sustainability. However, the sustainability of a PSS over traditional products and services is not automatic; it requires careful, intentional design. Despite a decade's progress in relevant literature, early-stage design assessment of a PSS – particularly from a life cycle standpoint and considering the social sustainability dimension – remains underexplored. This study introduces a framework for early-stage identification and analysis of potential environmental and social impacts within a PSS's life cycle to aid in decision-making and guide towards sustainable solutions. The framework's hotspot analysis, which combines life cycle assessment techniques, aims to pinpoint life cycle stages most susceptible to significant environmental and social impacts. Drawing on existing literature and expert evaluations, this approach offers designers preliminary insights into potential impacts, establishing a groundwork for comprehensive life cycle analysis once more detailed information on products, services, and organizational structures becomes available. The hotspot analysis not only addresses the lifecycle view of a PSS but also places emphasis on the oft-neglected social dimension of sustainability, marking an area ripe for further study. By supporting decision-making in the early design phase and encouraging scrutiny of various PSS concepts, this approach promotes the cultivation of sustainably-designed solutions.

Product-Service Systems for Circular Supply Chain Management: A Functional Approach

Growing environmental concerns, as well as market competitiveness, are inciting manufacturers to optimize the performance of their products throughout their entire lifecycle. To address these objectives, manufacturing, field service engineering and customer support should be aligned and should strive towards the same end-goal. While several studies have revolved around this context, the product-service system (PSS) approach has emerged as a promising way of meeting manufacturer, customer and environmental requirements alike. Nevertheless, most of these studies revolve around the design and development of a PSS, whilst a minimal amount of research has targeted its impact from the supply chain perspective, leaving aside inventory management. Consequently, the following study utilizes functional hierarchy modeling (FHM) and the PSS concept matrix to propose solutions that make it possible to meet customer requirements and improve the environmental performance and associated costs at the same time. An application at a medical equipment manufacturer brings forward the positive effects suggested by the research and reduces the aforementioned gaps. In detail, the results show a smaller variability in the supply of spare parts combined with optimized maintenance planning, which translates into lesser costs to the manufacturer, a prolonged product life cycle and a reduced environmental impact.

Towards a novel Business, Environmental and Social Screening Tool for Product-Service Systems (BESST PSS) design

Product-Service Systems (PSS) have recently regained attention in the literature and industry due to their potential to contribute to sustainability. PSS are also enjoying renewed attention, currently, as the large societal focus on circular economy (CE) enforces the potential of PSS. However, PSS are not more sustainable than traditional offerings by default and they, therefore, must be designed with sustainability in mind from the early design stages and their sustainability potential screened already at a conceptual design stage. Existing approaches to screen PSS sustainability have conspicuous shortcomings regarding their lack of comprehensiveness, usability and focus on the conceptual design stage deemed crucial for the sustainability level of the future offering. There is poor coverage, in the literature, of approaches to sustainability-driven PSS design, and no consolidated approach to supporting a comprehensive consideration of sustainability aspects in the early stages of PSS conceptualisation. This paper introduces a qualitative tool and a process that support decision-making through ex-ante screening of PSS concepts for manufacturing companies based on the triple-bottom-line (TBL) sustainable value potential over the PSS life cycle. The tool was developed iteratively through three action research cycles focused on theory development and theory testing, within a manufacturing company. The tool and the implementation process are perceived as an effective and efficient way to screen PSS concepts through a comprehensive, yet readily applicable and usable approach by the industry practitioners.

Revenue Mode Innovations for Product-Service Systems: Overcoming the Service Paradox

Industrial manufacturers aim to increase competitiveness by innovating their business model and offer product-service systems (PSS). However, firms often fail to exploit sufficient profits from PSS business model innovation (BMI). The role of revenue models to create and capture val-ue from innovating revenue streams for PSS is often neglected in practice and theory. The innova-tion literature has a profound understanding of the PSS concept and its value proposition design. However, it lacks knowledge and insights on how revenue model innovation (RMI) impacts the success and competitiveness of a PSS business model. From a perspective of the resource-dependence theory (RDT), we assume that RMI is a source of competitive advantage by reducing uncertainty and increasing interdependencies between economic actors of a PSS. Our research ap-plied a qualitative multiple case study with semi-structured interviews of leading PSS providers. We identified three dimensions of RMI-enabled customer value creation and provider value capture, reducing customer uncertainty and increasing dependence according to the RDT. Our research im-plies from the RDT perspective that PSS providers create a joint competitive advantage from RMI by giving additional value to their customers, which supports the power balance between both par-ties by a positive increase in interdependence. Our study contributes to the theoretical understanding of the role of RMI for PSS business model success. The study results will extend the theoretical knowledge about successful servitization through PSS and address its problem of exploiting reve-nues from the service business – the service paradox.

Triple Bottom Line impacts of traditional Product-Service Systems models: Myth or truth? A Natural Language Understanding approach

Currently, there is in the literature a debate concerning the real impact of Product-Service Systems (PSS) models on society. It is now stated that PSS does not necessarily lead to sustainable solutions in practice from a Triple Bottom Line (TBL) perspective. On the other hand, a promising approach, i.e. the Sustainable Product-Service Systems (SPSS) approach, has received attention from scholars within this debate. However, due to the novelty of this discussion, there is insufficient understanding of the synergies and divergences between both approaches regarding the potential to deliver TBL solutions to society. To address these lacks, this study examines the synergies and divergences between PSS and the emerging SPSS to deliver TBL solutions to society. Qualitative and quantitative research approaches were adopted to address the research questions. First, a structured literature review was employed. The literature analysis was segmented into two distinct periods (i.e., first period from 1990 to 2009, and the second period from 2010 to 2021). Next, the Natural Language Understanding (NLU) tools based on Artificial Intelligence (AI) and Neural Networks were applied to analyse the conceptual definitions retrieved from the relevant literature and extract new knowledge regarding both approaches. Third, the patterns of new knowledge were analysed against the literature in the area leading to research findings. Overall, findings indicate that, from a TBL perspective, SPSS is an emerging and promising approach in which the environmental and social dimensions are more salient than in the traditional PSS models. The study also unveils the central concepts related to both approaches in the extant literature. The article extends the current knowledge on PSS and SPSS, guiding the research communities interested in this area and unlocking the present and future challenges towards an effective sustainable-oriented economy. This article is a pioneering study to examine how the PSS and SPSS concepts have advanced towards TBL solutions in society.

Towards a framework to design product service system-based mobile phone waste management: A social media data analysis perspective

ABSTRACT Today, extensive universal concern about sustainable development, strict environmental legislation, and extended producer responsibility has become important incentives to consider end-of-life (EOL) products. Thus, the tremendous volume of mobile phone waste worldwide calls for the design of plans for managing products duringconsumption and the EOL phases to achieve sustainable treatment and betterenvironmental performance. Therefore, a product-service system (PSS) as a sustainable solution has received great attention. To achieve this goal, companies have shifted their focus to continuous improvement of PSS that contributes to better environmental performance and minimizing waste generation during the product life cycle. In this regard, this study suggests a new decision support system (DSS) model that supports the PSS design; that the proposed DSS analyzes the Twitter platform using an ontology-based text mining approach and a data mining-based technique based on the self-organizing map (SOM) to collect mobile phone defects from the Twitter database. Finally, a multi-objective optimization model was used to optimize economic and environmental impacts during the consumption and EOL phase based on mobile phone defects. This study shows that the PSS concepts can prevent mobile phone waste from arising in today’s modern worldby using social media data.

A study of the rebound effect on the product-service system: Why should it be a top priority?

The increasing intensity of competition, environmental pressures and diversification of customer demands call for integrated solutions, and this circumstance has propelled the product-service system (PSS) into a central position to satisfy consumer requirements and sustainability agendas. However, it is essential to emphasise that not all shifts toward PSS result in sustainability. Even when well-designed, PSS could generate unwanted side effects, usually referred to as rebound effects. Unfortunately, the study of rebound effects within PSS is constrained by the classical concept, which is concerned only with energy efficiency and its environmental impact. It is crucial to develop transitional awareness in observing the rebound effect on PSS by performing an in-depth assessment. This study aims to expand the discussion about the potential rebound effect within the PSS context and propose a framework for the PSS-rebound effect from a life cycle perspective. This study classifies and comprehensively depicts the rebound effect inside the PSS concept, highlighting the various features and cases/types of PSS based on current literature. Then a method is proposed to identify types of rebound effects, their causes and their period of occurrences within the product’s life cycle based on three sustainability characteristics. Case studies are provided to illustrate the application of the framework to identify the PSS-rebound effect relationship from the life cycle perspective. The result is beneficial for identifying potential rebound effects associated with PSS implementation to foster sustainability.

THE INTELLECTUAL DEVELOPMENT OF THE PRODUCT-SERVICE SYSTEM CONCEPT: A CITATION / CO-CITATION ANALYSIS

The concept of product-service system (PSS) can be described as a market proposition that increases the value of a product by adding additional services. The present paper aims to contribute to the current understanding of PSS research field by identifying and visualizing its theoretical evolution. A citation and co-citation bibliometric analysis was conducted and it was possible to identify that PSS theory was supported by an integrated approach of the servitization (VANDERMERWE; RADA, 1988)and the service-dominant logic concepts. A co-citation map enables the visual representation of the intellectual structure of PSS research field contributing to better identify gaps and opportunities for future research

Conceptual Solution Decision Based on Rough Sets and Shapley Value for Product-Service System: Customer Value-Economic Objective Trade-Off Perspective

The product service system (PSS), as a design concept for integrated products and services, needs to be evaluated in the early design stage to maximize the value for stakeholders of the PSS concept, which is a crucial task for enterprises. However, existing methods focus on the ranking and value assessment of PSS evaluation criteria (e.g., quality, sustainability, cost), ignoring the needs conflict between customer value and economic objectives in PSS design, resulting in decision results that are not applicable to industrial enterprises. Furthermore, the influence of weight preference and uncertain information on solution evaluation is seldom considered when calculating the weight of each criterion. To fill this gap, integrating rough sets and the Shapley value decision approach for product-service system design considering customer value-economic objective trade-off is proposed, which mainly includes two parts: firstly, the best worst method (BWM) and the entropy weight method are integrated to obtain the comprehensive weight of evaluation criteria in the customer value and economic objectives; secondly, the Shapley value method in the coalition game is used to solve the optimal expectation allocation of the two objectives, so as to select the solution closest to the allocation, i.e., the optimal solution. In addition, rough set techniques are used to capture and integrate subjective assessment information originating from DMs under uncertainty. Finally, a case study of the electric forklift design is illustrated to verify the proposed decision model. The decision results show that this approach is more reliable through sensitivity and comparison analysis, and provide a valuable recommendation for enterprises to consider product service in forklift design.

Towards territorial product-service systems: A framework linking resources, networks and value creation

While many models for sustainable product-service systems (PSS) integrate the multi-actor perspective, few provide insights on how the territory in which actors implement the system influences its sustainability. This paper explores the implementation of a territorial PSS at a city or regional scale as a means to structuring value networks and enhancing its sustainability potential. The research combines a multidisciplinary literature review with two exploratory sustainable PSS cases in packaging and cloth baby diapers. The paper proposes a framework explaining how sustainable PSS providers develop territorial networks that consider a diversity of actors from civil, industrial, and public spheres to mobilize resources for value creation at organizational, network, and territorial levels. It identifies contextual factors, such as proximity, social embeddedness of relations, and the visions that influence the consolidation and sustainability of the territorial PSS networks. The empirical cases show the development of territorial networks enhances embed social relations among actors and enables the sustainable PSS concept to adapt to locally articulated sustainability principles and priorities. The paper discusses the implications of this approach for PSS for sustainability managers and designers. The study fills a gap by showing the importance of integrating a diversity of territorial actors as a pre-condition for PSS to contribute to the sustainability transitions and resilience of territories. Future research may validate the proposed framework and focus on identifying opportunities and barriers for the territorial PSS approach in different contexts such as industries and company sizes.

CHINESE PRODUCT-SERVICE SYSTEM INNOVATIONS ENABLED VIA GOVERNMENTAL POLICIES: THE E-SCOOTER CASE

AbstractTogether with increasingly saturated and commoditized global markets companies are driven to shift their business focus, adopting a strategy where customer perceived value is in the spotlight, and where products are bundled with services to offer Product-Service Systems (PSS).In this research we study the emergence of PSS solutions in the Chinese market via a selected case study on e-scooters, based on the governmental decision to ban fossil-fuel scooters in the late 90s and how this has spurred both a fossil-to-electric transformation and a product-to-function transformation.As seen in this research PSS is also an approach that is working well in the Eastern society and especially in China, based on governmental policies. It is gradually being adopted and applied in local industries significantly by China's leading internet companies (Didi, Alibaba etc). The PSS concept represented by e-bike cases in China has gradually penetrated into different industries. With governmental decisions as the key turn-point, it can be seen in practice and development that China's related service industry is using e-bike PSS to carry out the new business model from selling e-bikes to providing service-oriented solutions.

A function-oriented optimising approach for smart product service systems at the conceptual design stage: A perspective from the digital twin framework

The smart product service system (PSS), as an emerging business paradigm for value proportions, has attracted increasing interests from multidisciplinary backgrounds; this state of affairs has been triggered by advances in information technologies such as the Internet of Things (IoT), smart connected products (SCPs), and many others. In order to achieve a successful Smart PSS, the optimising approach plays a significant role in the development of Smart PSS, particularly at the conceptual design stage, by increasing the practical value of such systems and sharpening their marketing competitiveness. However, few studies have addressed the optimisation of Smart PSS, as it is a newly coined term with high degrees of uncertainty and complexity. The key to successful Smart PSS development is improving its systematic ideality to sharpen its competitiveness in the market. To fill the research gap, this paper proposes a function-oriented Smart PSS optimising approach based on the framework of digital twins (DT), with the aim of improving Smart PSS solutions at the conceptual design stage. To achieve this, a hybrid modelling approach for Smart PSS is first proposed by integrating the function modelling approach derived from the theory of inventive problem solving and the five-dimensional DT framework, which is applied to analyse the coupling and correlations among elements in both the physical and digital spaces. Subsequently, a triangular fuzzy number (TFN)-based calculation algorithm was applied to evaluate and rank the functional values of all components constituting the targeted Smart PSS with reference to their functional importance and functional roles. Based on the results of this functional value ranking, an optimising method is proposed to refine the Smart PSS concept by increasing the overall systematic ideality through the implementation of trimming, a systematic innovative tool that emphasises ‘reduction’ in solving engineering design problems. Finally, an intelligent cleaning robot Smart PSS is used as an illustrative case to address the feasibility of the proposed method.

Realizing a Circular Concrete Industry in Denmark through an Integrated Product, Service and System Perspective

Concrete is the most commonly used material worldwide, often associated with an irreversible production process and waste generation at the end-of-life. As such, the concrete industry holds large untapped potentials for moving towards more circular economy (CE) practices. Product service system (PSS) offerings incentivize CE through extending product use, improving product performance and developing responsible end-of-life and take-back strategies. A broader definition of the concept of PSS is suggested, and a conceptual framework for realizing CE at the ‘product’, ‘service’ and ‘system’ dimensions is provided. The framework is applied to the case of concrete industry in Denmark. The aim was to cast new light on how the concrete industry can realize CE through a broader ‘product’, as well as ‘service’ and ‘system’ perspective. The selected case is analyzed through nine semi-structured interviews, additional secondary data, and follow-up dialogue with selected stakeholders. Results indicate a ‘product’ perspective may lead to savings on input material cost, improved efficiency of resource use, and reduced concrete waste quantities. A ‘service’ perspective can bring new market opportunities for concrete producers to adapt solutions to users’ needs. A ‘system’ focus calls for new forms of organization and collaboration, as well as the expansion of networks within and across different stakeholder groups.

Can Material and Energy Be Saved by Differentiating Water Quality Targets in the Water Purification Process?

The current organization of water supply systems demands drinking standards for all the households’ usage of water. Few dual water systems, i.e., systems in which the quality of the water supplied is differentiated by types of use, exist but are mainly circumscribed to developing countries. Besides, bath and showers are so far considered as a potable use of water despite only drinking and cooking activities requiring the high-quality standards of potable water. The present work demonstrates how the principles of dual water systems can be incorporated into the sustainable concept of product-service system (PSS) using a dual water system of a municipal water supply treatment plant in France as a case study. The PSS is based on the water quality, and the bathing activity of households is considered with a dedicated standard for the first time. Two systems are considered, S1 and S2, supplied with the same raw water quality and treated with drinking (S1) bathing standards (S2). The quality parameters considered are total organic carbon (TOC) and turbidity (T) and the potential savings related to costs, material, and energy consumptions are assessed using EVALEAU as a process modeling tool. The treatment lines consisted of powdered activated carbon (PAC) addition, coagulation, flocculation, settling, and rapid sand filtration. Results show that material consumption can be reduced by 41% mainly through the decrease in chemical consumption associated with the change of requirement for the TOC parameter. On the opposite, energy consumption was found dependent on the water of volume treated rather than its quality leading to only marginal savings. The cost was decreased by 37% as a result of the reduction of the chemicals consumed.

A rough–fuzzy approach integrating best–worst method and data envelopment analysis to multi-criteria selection of smart product service module

The revolutionary development and implementation of smart technologies have triggered the manufacturers’ servitization trend towards smart product service system (PSS). Accurate selection of smart product service (SPS) module is critical to successful planning and development of smart PSS concept. This study constructs a list of criteria for SPS module selection from the perspectives of service implementation, value symbiosis and smart capability. The selection can be deemed as a multi-criteria decision-making process including two parts: weight determination of criteria and module ranking, in which the intrapersonal linguistic ambiguousness and interpersonal preference randomness are involved. The best–worst method (BWM) is widely acknowledged as an efficient method for weight determination due to its superiority in quickly finding optimal weight with scant decision data. The data envelopment analysis (DEA) method is proven feasible to prioritize alternatives with cost-based and benefit-based criteria. However, these two methods cannot handle the uncertainties involved in the selection process which may lead to imprecise results. Moreover, the previous research rarely studies simultaneous handling of these two types of uncertainty in the realm of BWM and DEA. Therefore, the current study proposes a novel rough–fuzzy BWM-DEA approach to SPS module selection, with fully capturing both the intrapersonal and interpersonal uncertainties. The application of the proposed approach in the smart vehicle service module selection and the comparisons with other methods demonstrate the validity and effectiveness of the proposed approach.

The player-interface method: a structured approach to support product-service systems concept generation

ABSTRACTFor manufacturing companies, the integration of service elements to support product offering has become a key factor in gaining competitive advantage. Product-Service Systems (PSSs) are value offerings that combine tangible products and intangible services. To date, their design process is still critical. There are several aspects that designers need to consider, including (i) the variety of PSS elements, (ii) potential interactions between PSS players and (iii) lasting customer relationships. Considering these issues, this paper proposes a novel operative tool, herein named Player-Interface (PI) method, to support designers in the definition of new PSS concepts. The method helps designers to activate new service or product elements based on the analysis of the possible interactions between the PSS players. The description is supported by a case study in the manufacturing sector.

Modelo metodológico de diseño de sistemas producto-servicio (M.M.SPS) en el contexto empresarial colombiano : una investigación desde el diseño.

La noción de sostenibilidad surge al afrontar las consecuencias de los impactos ambientales ocasionados por la acelerada industrialización. Su reto consiste en cambiar el fin de la economía liberal: la utilidad por un equilibrio entre las variables sociales, ambientales y económicas. Entre las soluciones exploradas, la disciplina del diseño desarrolló el concepto de sistemas producto-servicio (SPS), modelo de negocios no tradicionales que buscan proporcionar valor ambiental a través del ecodiseño, valor económico con configuraciones innovadoras de redes y valor social diseñando para el usuario. La investigación reconoce en los SPS una poderosa opción para transitar hacia la sostenibilidad y generar competitividad, razón por la cual se han puesto en práctica en varios países europeos; no obstante, de acuerdo con las Naciones Unidas, su implementación es baja en países de Latinoamérica debido a la ausencia de conocimiento y tecnológica, a la falta de metodologías de diseño, a la carencia de capacidades de emprendimiento, experiencia en la gestión de servicios y un marco legal de apoyo (UNEP, 2002). La presente investigación busca generar un aporte desde el diseño para sobrepasar estas barreras de implementación, mediante el desarrollo de una metodología que posibilite la creación de sistemas productoservicio en el contexto colombiano. El enfoque metodológico utilizado es cualitativo, y se seleccionó el método de caso de estudio tipo múltiple. El resultado principal de la investigación es el Modelo Metodológico de Aproximación a los sistemas producto-servicio (M.M.SPS), mientras que entre las conclusiones se identifican una brecha en conocimientos y capacidades de diseño, innovación, sostenibilidad y gerencia para desarrollar soluciones SPS; un alto potencial de contribución del diseño a través de nuevos roles del diseñador y herramientas de comunicación, visualización e interacción, y la necesidad de optimizar la capacidad de configurar redes empresariales que posibiliten los SPS.

Design and manufacturing of a smart mobility platform’s context awareness and path planning module: A PSS approach

A smart mobility platform aiding in guidance of disabled people is a concept that can facilitate people’s everyday life. However, design and manufacturing of such a system faces many issues in terms of agility in design, implementation and usability verification. To this end, the concept of Product-Service System (PSS) seems to be the solution; being an emerging concept oriented towards the dematerialisation of the economy, meeting also the requirement of manufacturing industries to cope with the radical changes in the global market. In this study, the development of a context awareness and path planning system under the prism of PSSs is examined. This module is considered to be promoted as a pay per service unit that can be implemented in different operational scenarios and environments. The key objective is to deliver the obstacle avoidance and path planning functionality and add value to the customer, but at the same keep the production lean and flexible. To this end, Round Robin parts are presented, taking into account mounts and jigs for controllers dealing with supervised machine learning techniques and path planning, light-weight system-of-sensors and structural integrity of the module. The concept evaluation is outlined through a case study based on the integration of the system in a smart mobility platform to provide autonomous mobility. The mobility platform is expected to operate within a predefined area, characterized by a complex environment.

A tailor-made learning environment workspace for generation y graduates using product service system concept

This paper presents a workspace design of a tailor-made learning environment for students using the product-service systems (PSS) concept. Existing research regarding workspace design focuses on the design of the interior of classrooms to ensure that the learning process proceeds with minimum stress and maximum effectiveness. None of the current research had discussed the workspace outside of the classroom. Therefore, the main objective of this study is to propose a learning environment workspace in which students can gather, study, relax, socialize, eat, and work during class gaps. For this purpose, a questionnaire was distributed to identify the behavior of the users to generate a list of requirements in the development of the learning workspace. This paper focused on students at the Engineering Faculty and the learning environment workspace was called the OneForAll Center. Out of 10 functions of the proposed OneForAll Center, only four functions had the highest priority: a space to use a laptop and internet connection, a television, a vending machine and a printing section. The OneForAll Center has been illustrated in a 3D model and shown to the students, in which most of them agreed with the proposed services and facilities such as a space to use the laptop and internet connection and a printing section with a printing service. The OneForAll Center has been identified as a solution to improve learning outside the classroom, specifically to the provision of services to students.

Explore and evaluate innovative value propositions for smart product service system: A novel graphics-based rough-fuzzy DEMATEL method

Abstract The rapid development of advanced information and communication technology enables the mainstream trend of manufacturing value propositions towards smart product service system (PSS). Prospect innovative value propositions (IVPs) emerge in the context of smart PSS. The IVPs analysis plays a critical role in the successful planning and design of smart PSS business model, which includes two key steps: identification and evaluation. However, the existing research rarely systematically explore what value propositions can be identified in the emerging field of smart PSS. Thus, this study conducts a comprehensive IVPs identification through literature review and prioritize these IVPs to provide support for later smart PSS concept design. Compared to other evaluation methods, the Decision Making Trial and Evaluation Laboratory (DEMATEL) presents higher effectiveness to evaluate the interrelationship and importance degree of the identified IVPs. Moreover, the previous fuzzy-based DEMATEL is feasible to handle intrapersonal uncertainty (individual linguistic vagueness), and the previous rough-based DEMATEL can effectively manipulate the interpersonal uncertainty (group preference diversity). Nevertheless, there are few researches on simultaneous manipulation of the two kinds of uncertainty which may lead to inaccurate evaluation results. Therefore, this study develops a novel graphics-based rough-fuzzy DEMATEL method for IVPs evaluation. The effectiveness and accuracy of the proposed evaluation method are illustrated through the application in the smart vehicle service system and the comparisons with several different methods. The proposed evaluation model can provide more accurate and informative results, because it integrates the merits of fuzzy set in coping with the intrapersonal uncertainty and the strength of rough set in handling interpersonal uncertainty, and supports to present decision inconsistency along with the final weights based on a proposed graphics-based operator.