Lean (production) | EPFL Graph Search

vignette|upright=1.3|Modèle du système « Lean production ». Le terme lean (de l'anglais lean, littéralement « maigre », « sans gras », « dégraissé ») sert à qualifier une méthode de gestion de la production qui se concentre sur la « gestion sans gaspillage », ou « gestion allégée » ou encore gestion « au plus juste ». L'école de gestion lean trouve ses sources au Japon dans le système de production de Toyota ou SPT (en anglais Toyota Production System ou TPS). L'école de philosophie du lean est marquée (dans la lignée du taylorisme) par la recherche de la performance (en matière de productivité, de qualité, de délais, et enfin de coûts), censée être plus facile à atteindre par l'amélioration continue et l'élimination des gaspillages (muda en japonais), afin d'améliorer la valeur globale pour le client. Les mudas sont au nombre de sept : surproduction, attentes, transport, étapes inutiles, stocks, mouvements inutiles, corrections/retouches. Formalisée aux États-Unis dans les années

Product Quality Improvement Policies in Industry 4.0: Characteristics, Enabling Factors, Barriers, and Evolution Toward Zero Defect Manufacturing

Dimitrios Kyritsis, Gökan May, Foivos Psarommatis Giannakopoulos

In the competitive market of manufacturing, quality is a criterion of primary importance in order to win market share. Quality improvement must be coupled with performance point of view. Lean Manufacturing, Six Sigma, Lean Six Sigma, Total Quality Management, Theory of Constraints, and their combination are philosophies dedicated to this goal. This study is a literature review on the implementation of these philosophies to improve quality of processes and products in a system, and also covers the commonalities and differences with Zero Defect Manufacturing (ZDM) philosophy. In this study, 45 articles have been analyzed. These articles have been selected by a research on several scientific libraries with specific keywords. The methodology is based on a list of information extracted from each paper. The data searched are on the tool selections, critical factors of implementations and the benefits obtained from them. Based on the review and analysis of the literature and practices, we provide the top 10 main components of the tools used for quality improvement, enabling factors, benefits, and barriers to implementation. Moreover, we present and discuss categorization of quality improvement methods and the way toward ZDM. The need of standardized toolkits for different levels of maturity in quality management systems and a better education have been enlightened. Thanks to technological improvement in information flow management, ZDM seems close to be achieved even though some new risks and wastes have to be taken care of within the implementation.

2020

Towards Seamless Continuation of Knowledge in Product Lifecycle Management

Apostolos Perdikakis

The current ICT for manufacturing landscape is characterized by scattered data formats, tools and processes dedicated to different phases in the product lifecycle. Due to the diversity of tools and data formats, manufacturing struggles to cope with new trends in this area. What is clearly missing in the current ICT landscape for manufacturing is an integrated, holistic view on data about products to be manufactured, resources (including human resources) and processes across the full product lifecycle. There is a need to formalize knowledge for the automatic integration in existing engineering tools. In this work ontology-based semantics were exploited to develop machine-understandable models, which are able to understand the meaning of the data and information they contain. The system developed using semantic web methods and tools is designed to support interoperability and data integration, as well as lead a way towards the usage of information contained in the system to extract useful knowledge. This knowledge may provide feedback for improving the design of future generations of products. Thus, the concept of seamless continuation of knowledge all along product-system lifecycles is introduced.The first step of this work was to study the state-of-the-art in PLM and Semantic web Technologies. This included theoretical background in concepts like Beginning Of Life (BOL), Middle Of Life (MOL) and End Of Life (EOL) regarding PLM as well as the definition and theoretical background of Ontologies and Semantic Web Technologies. After completing the study of theoretical background, more advanced research concepts and methodologies for both domains were thoroughly analysed. Examples include Closed Loop Lifecycle Management (CL2M) for PLM and NEON Method-ology for Ontology engineering. The next logical step followed was to find and discover relevant standards like STEP for PLM and W3C standards for Ontologies and Semantic Web Technologies. The engineering aspect of this study imposed the review of available tools both for PLM and Ontology Engineering. Ontology development tools like Protégé, TopBraid composer and Anzo Ontology editor were studied. More advanced software solutions for applications of the semantic web were also studied. Examples include Anzo Enterprise and the Open Semantic Framework. Inspiration also came from previous European projects like EC FP6 Promise. The problem of discontinuation, even after an Ontology model is created, is evident in most of the applications studied as background of this work. Ontology models have to be exploitable and that requires a framework of which they can be part of. The research for successful implementations of ontology driven frameworks was imperative. At first, the open seman-tic framework (osf) was the software stack that came into focus. After being thoroughly studied, it proved difficult to deploy and maintain, for it had still many problematic areas with its configuration and required people with very ad-vanced software skills (both in programing and system configuration). Nevertheless, the examples of use are promis-ing and give many ideas for exploitation. This finding triggered the efforts towards the definition and application of the solution proposed in this work, which has the following characteristics. First and most important, the solution is easy to deploy and maintain, since it is targeting SMEs and large enterprises that want to test the capabilities of the proposed[...]

EPFL2015

STEP-NC digital thread for additive manufacturing: data model, implementation and validation

Pascal Mognol, Ian Anthony Stroud

Substantial progress and development in additive manufacturing (AM) technologies have been realised during the last decade but have hardly been implemented on AM systems due to old numerical solutions still used by the AM digital thread, for instance STL (1987) and G-code (ISO 6963, 1982). In this field, more traditional processes like machining have challenged this issue by adopting the Standard for the Exchange of Product model data compliant Numerical Control (STEP-NC) standard that enables advanced and intelligent manufacturing by taking advantage of the full computing performance of numerical controllers in manufacturing machines. This standard integrates the whole digital chain (CAD-CAM-CAPP-CNC-CMM) in a unique file with information on design and manufacturing and enables manufacturing of high-value products directly without numerical data conversion or post-processing. This study presents a new STEP-NC data model for AM technologies developed with the ISO TC184/SC1/WG7 committee. A STEP-NC platform initially developed for machining processes has been adapted to implement and validate the AM data model. It enables AM directly from a STEP-NC file, as well as hybrid manufacturing (AM and machining), and allows integration of several optimisation and simulation modules that extend the possibility of advanced and intelligent AM, for instance in-process manufacturing optimisation.

TAYLOR & FRANCIS LTD2018

Towards Seamless Continuation of Knowledge in Product Lifecycle Management

Apostolos Perdikakis

EPFL2015