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Contrôle dynamique du Demand Driven Sales and Operations Planning
No full textThe Demand Driven Material Requirements Planning (DDMRP) methodology revolves around the use of inventory buffers. The sizes of these buffers evolve dynamically and need several parameters to do so. Hence, deciding on relevant values for these parameters is a crucial step to make sure that buffers both fit the actual demand and are not needlessly oversized. These research works focus on dynamically updating these parameters in a context where demand may not be stable. The process responsible for such an update is called Demand Driven Sales and Operations Planning (DDS&OP). Thanks to a range of discrete events simulation experiments, we compared the behaviours of a theoretical flow shop under the DDMRP principles with different combinations of dynamical policies for parameter updates. These policies come from both scientific literature and DDMRP experts feedback. In order to reach broader conclusions, we also submitted the flow shop to a range of different demand profiles. This manuscript also challenges theoretical results on an industrial case to test both the relevance and feasibility of the policies. Promising experimental results show that dynamical control of the parameters is suited when demand variation is high. They also hint at the possibility to simplify parameter updates by identifying which of them may be kept contant and in which cases. Lastly, industrial simulations raise the problems of nervousness and complexity for dynamical control of larger cases.La méthodologie Demand Driven Material Requirements Planning (DDMRP) est caractérisée par l'utilisation de buffers de stock dont le dimensionnement est dynamique et fait appel à plusieurs paramètres. Décider des valeurs pertinentes pour ces paramètres est une étape essentielle pour que la taille des buffers soit adaptée à la demande sans toutefois être trop élevée. Ces travaux de recherche se concentrent sur la mise à jour dynamique de ces paramètres, dans un contexte où la demande varie. Le processus responsable de cette mise à jour est appelé Demand Driven Sales and Operations Planning (DDS&OP). À travers un ensemble d'expériences de simulation par événements discrets, on se propose de comparer le comportement d'un atelier théorique (cas d'école) géré en DDMRP et régi par diverses combinaisons de politiques de paramétrage. Ces politiques ont été tirées de la littérature, mais également d'entretiens réalisés avec des experts du DDMRP. Cet atelier est également soumis à plusieurs types de demandes, de façon à généraliser les conclusions de l'étude. Ces travaux étendent également les expériences à un cas de taille industrielle afin d'évaluer la pertinence et la faisabilité des politiques proposées. Les résultats expérimentaux montrent un intérêt pour le contrôle dynamique de certains des paramètres des ateliers gérés en DDMRP, principalement dans le cas de demandes connaissant de fortes variations. Ils montrent également la possibilité de simplifier la gestion des paramètres en en gardant une partie constante. Enfin, à partir du cas industriel, on envisage la problématique de la nervosité et de la complexité impliquée par le paramétrage dynamique d'ateliers plus complexes
Fire behaviour of hybrid filament-wound single and adhesively bonded composites tubes under static pressure
No full textInternational audienceThe present work aims to experimentally investigate the fire behaviour of water-filled E glass reinforced thermoset resin hybrid filament-wound composites tubes under static pressure. Heretofore, fire endurance tests have been conducted on single and adhesively bonded tubes manufactured by CTRA Company. Furthermore, internal pressure tests until failure have been performed on the burnt single and burnt joined tubes in order to quantify their abilities to contain the fluid after being exposed to heat flux. A comparison between the pressure behaviour of exposed to fire (burnt) and non-exposed tubes (single and joined) was also inspected. The identification of the fire-induced damage mechanisms of the tubes was performed through optical microscopy, Scanning Electron Microscopy (SEM) and X-ray tomographic observations. Finally, the thermal analysis was carried-out on burnt specimens in order to better understand the multiphysical phenomenon taking place during the fire endurance tests. The experimental results have revealed that the combustion process of both single and joined tubes was described in four steps namely tube heating, resin degradation, ignition and flame decay. Moreover, it was found that no leakage was witnessed on the tubes (single and joined) outer surfaces during the fire endurance tests. The comparison between the pressure behaviour of the burnt single tube and the burnt joined one has proved that the single tube is much resistant under internal pressure loading than the burnt joined tube. Finally, the fire-induced damage included matrix cracking and delamination between the tube plies which was noticed from microscopic observations
AdoBPRIM: Towards a New Healthcare Risk-aware Business Process Management Tool
No full textInternational audiencePerforming risk management in healthcare facilities is particularly difficult due to the highly dynamic, complex, and multi-disciplinary nature of healthcare processes like the Medication Use Process (MUP). Risk-aware Business Process Management (R-BPM) is a promising approach to obtain a better understanding of such processes by identifying and analyzing corresponding risks. However, not all R-BPM approaches perform well in capturing the complexity of clinical processes. In this work, we introduce a new R-BPM framework called BPRIM that allows the identification and the analysis of medication error risks related to the complex medication use process. BPRIM is implemented using the ADOxx meta-modelling platform and then tested in a real case study. The tool is specific to the case study, but the framework can be used also in other healthcare processes
Ultra-fast heat dissipating aerogels derived from polyaniline anchored cellulose nanofibers as sustainable microwave absorbers
No full textInternational audienceElectromagnetic (EM) pollution is ubiquitous and has soared to a great extent in the past few decades. The use of plant sourced cellulose nanofibers to fabricate sustainable and high performance electromagnetic shielding materials is foreseen as a green solution by the electronics industry to address this unseen pollutant. In this view, we report a facile and environmentally benign strategy to synthesize ultra-light and highly conductive aerogels derived from cellulose nanofibers (CNF) decorated with polyaniline (PANI) via a simple in-situ polymerization and subsequent freeze drying process devoid of any volatile organic solvents. The obtained conductive aerogels exhibited density as low as 0.01925 g/cc with a maximum EMI shielding value −32 dB in X band region. These porous shields demonstrated strong microwave absorption behavior (95 %) with minimal reflection (5 %) coupled with high specific EMI SE value ∼1667 dB.cm3. g−1 which make these aerogels a potential candidate for use in telecommunication, military and defense applications
Humanitarian Response Readiness Metric for More Effective Relief Operations
No full textInternational audienceNatural disasters are affecting millions of people every year and causing billions of dollars of damage. Humanitarian relief operations aim to alleviate the suffering of the victims after the disaster. Performance of humanitarian relief can be measured with its efficiency and effectiveness. Coverage and speed of humanitarian response are two main components of its effectiveness. In this paper, we are trying to measure the response readiness of a humanitarian supply chain for an immediate disaster, by developing a metric called “humanitarian response readiness”. With this metric, we are measuring the coverage and speed capabilities of the humanitarian supply chain together, with a priori measurement approach
Editorial for the Special Issue: Energy Security and Chemical Engineering Congress (ESChE) 2019, Penang, Malaysia
No full textInternational audienc
Towards a Metamodel supporting E-government Collaborative Business Processes Management within a Service-based Interoperability Platform
No full textInternational audienceInteroperability between different organizations is a complex task, where a key element is to be able to define without ambiguity the concepts that are involved in each domain and their relations. A key aspect for enabling e-government is the technological support for complex interaction scenarios, defining collaborative Business Processes (BPs) that are the basis for these interactions. E-government collaborative BPs involve several and heterogeneous participants: organizations, partners, and users, with different capabilities, needs, and available technical support. The goal of this paper is to present ongoing research on e-government cross-organizational collaborative BPs support in a service-based interoperability platform. This proposal is focused on the formalization and exploitation of e-government knowledge and information (i.e., metamodels and ontologies) to improve the definition, automated generation, control, monitoring and improvement of e-government collaborative BPs
Eco-Stock® - Solution de stockage de la chaleur compétitive : Etude de la robustesse
No full textNational audienceThe company Eco-Tech Ceram developed an industrial scale thermal storage designed to recover waste heat up to 600°C:the Eco-Stock®.This unit of 2 MWhThcontains 16 tons of refractory ceramic. The robustness regardingthe variation of inlet temperature and flowrate is tested to show that the Eco-Stock®matches with the constraints of waste heat sources,involving sharp variation temperature and flowrate but also stand-by period.La sociétéEco-Tech Ceram a développé un stockage thermique de taille industrielle pour la valorisation dechaleur fatale jusqu’à 600°C: l’Eco-Stock®. Il s’agit d’une unité de 2 MWhTh, contenant16 t de céramique réfractaire. La robustesse aux variations de température et de débit est testée afin de montrer que l’Eco-Stock®est adapté aux contraintes des gisements de chaleur fatale,impliquant defortes variations de température, de débit et des périodes de stand-by
Using Approximation within Constraint Programming to Solve the Parallel Machine Scheduling Problem with Additional Unit Resources
No full textInternational audienceIn this paper, we consider the Parallel Machine Scheduling Problem with Additional Unit Resources, which consists in scheduling a set of n jobs on m parallel unrelated machines and subject to exactly one of r unit resources. This problem arises from the download of acquisitions from satellites to ground stations. We first introduce two baseline constraint models for this problem. Then, we build on an approximation algorithm for this problem, and we discuss about the efficiency of designing an improved constraint model based on these approximation results. In particular, we introduce new constraints that restrict search to executions of the approximation algorithm. Finally, we report experimental data demonstrating that this model significantly outperforms the two reference models
Environmental and exergetic life cycle assessment of incineration- and gasification-based waste to energy systems in China
No full textInternational audienceThe clean and efficient energy production from municipal solid waste (MSW) is highly desirable due to increasing energy demand and environmental concerns. In this study, four incineration- (S1) and gasification-based (S2 with combustion boiler, S3 with gas turbine/combined cycle and S4 with internal combustion engine) MSW treatments were compared using methods of environmental life cycle assessment (LCA) and exergetic life cycle assessment (ELCA). LCA was applied to measure the environmental performances and ELCA was supplemented to reflect the thermodynamics efficiencies. Afterwards, cumulative degree of perfection (CDP) and abatement exergy (AbatCExC) efficiency of the considered systems were also calculated to determine the imperfection and environmental sustainability of the processes. Results showed that gasification-based systems were effective to mitigate the environmental impacts of acidification, nutrient enrichment, and photochemical ozone formation potential, but caused higher global warming impacts. The S3 system exhibited the best performance from both environmental and exergetic perspective, due to its high net efficiency of electricity generation and low exhaust emission into air. Results from ELCA indicated that the rest two gasification-based systems (S2 and S4) were inefficient as compared to MSW direct incineration, mainly due to auxiliary energy consumption for MSW pretreatment and more conversion steps. The CDP and AbatCExC of the systems in descending order was expressed as S3 system > S1 system > S2 system > S4 system