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International audience; The paper presents two new methods for engineering change propagation. These methods evaluate the product change impact and predict the change propagation effect. The two change propagation methods (i) Layer propagation method and (ii) Path propagation method, are applied to the dependency graph and based on the Depth First Search and the Breadth First Search algorithms. The dependency graph links two product parameters with their functional dependency. By using these two methods, designers can better understand the direct change impact by product parameters interactions and the indirect change effect via the propagation.

International audience; A product is redesigned by integrating structural or functional modifications to satisfy new needs or requirements. Iterations are also necessary to fine-tune product definition during the initial design process. In both cases, engineering changes are the means by which the product evolves. However, changes are propagated from component to components and from function to functions, leading to nonvalue development activities with extra costs and delays. These engineering changes may have harmful impacts on industrialization and manufacturing; they can drastically hinder efforts to ensure faster time-to-market. Research works currently seek to model, predict, analyze, and assess the impacts of engineering changes and their propagations. This article focuses on changes in a two-dimensional geometrical product model and proposes a new change prediction approach based on two steps. First, the dependencies between the parameters of structural components are identified through experiments. These dependencies are characterized qualitatively, quantitatively, and by formal equations. The changes are then propagated through the network of dependencies, and their consequences are computed. A geometric two-dimensional model of a bicycle is used to illustrate the approach. The results are discussed, and the main contributions of the approach are highlighted while further research paths are presented at the end of this article.

International audience; A product is redesigned by integrating structural or functional modifications to satisfy new needs or requirements. Iterations are also necessary to fine-tune product definition during the initial design process. In both cases, engineering changes are the means by which the product evolves. However, changes are propagated from component to components and from function to functions, leading to non-value development activities with extra costs and delays. These engineering changes may have harmful impacts on industrialization and manufacturing; they can drastically hinder efforts to ensure faster time-to-market. Research works currently seek to model, predict, analyze and assess the impacts of engineering changes and their propagations. The present paper focuses on changes in a 2D geometrical product model and proposes a new change prediction approach based on two steps. First, the dependencies between the parameters of structural components are identified through experiments. These dependencies are characterized qualitatively, quantitatively and by formal equations. The changes are then propagated through the network of dependencies and their consequences are computed. A geometric 2D model of a bicycle is used to illustrate the approach. The results are discussed and the main contributions of the approach are highlighted while further research paths are presented at the end of the paper.

International audience; During the product’s life cycle, it can be re-designed due to received requests for new improvement. One or more changes can be applied on the product in order to adapt or upgrade it. These changes can have serious impacts. Some of the change impact can be partly predictable while some other unexpected propagation of the change can still occur. Despite this risk, the industry does not currently have a clear approach to evaluate and represent the propagation of changes and minimize their consequence. The main objective of this work is to characterise this change impact by identification of the dependencies among product components, which is a first and necessary step to evaluate change propagation. We develop a novel approach based on Design Structure Matrix to identify and characterise the type of dependency existent between two dimensions. Findings show that functional dependency is more detailed than quantitative and qualitative dependency characterisation, already used in the literature.

National audience; La re-conception d’un produit déjà existant dans le marché est un besoin courant dans de nombreux secteurs industriels. Le modèle du produit modifié est généralement issu de celui existant en ne changeant que quelques paramètres de conception. Par contre, ce renouvellement est rarement simple et un petit changement dans un élément du produit peut causer de nombreux changements sur les autres éléments du produit. Ces changements peuvent avoir de graves impacts. Malgré ce risque, l'industrie ne dispose pas actuellement d'une approche claire pour évaluer et représenter la propagation des modifications et minimiser leurs effets.

International audience; Engineering change management is a research field in which the goal is to deal with modifications of products and systems. Methods and tools are set up to predict more efficiently the propagation of changes or to assess the consequences of these changes. This paper addresses the fundamental research question of dependency identification in a product. We propose an approach based on the use of specialised support tools and knowledge to map the dependency links among components or parameters of a product. These dependencies are expressed quantitatively, qualitatively or as a polynomial function. The general approach is here applied to a geometric 2D model of a bicycle. The analysis of the obtained dependency graph gives insights to designers for modification of existing products or for creation of new robust products.

International audience; Products in engineering design are susceptible to be changed. A change in one product element can involve changes in other elements. While, in most cases, the change impact can be partly predictable, unexpected propagation of the change can occur. The main objective of this work is to characterise this change impact in order to predict as finely as possible the consequence of the product change on its structure and its functions. We develop a process to explain how to use regression analysis to identify the type of dependency existent between two dimensions. Findings show that, although qualitative dependency, already used in the literature, aids to predict either the increase or decrease of the affected dimension’s value after a change in instigating dimension’s value, functional dependency offers an effective way for characterising the relationship between two dimensions and translate it into a function which can be helpful in the further works of change propagation analysis.

The overall goal of this Ph.D. research is to provide reference models, support me- thods and tools that simulate change propagations in a Product Development (PD) project to assist decision-makings. We firstly establish a change analysis framework of modeling the context of change occurrence and propagation by taking into account the multiple knowledge areas of PD project simultaneously. Under the framework, we propose the conceptual models of change occurrence and change propagation that pro- vide a qualitative method to identify change and change propagation and imply some characteristics of change propagations. Relying on that, we suggest the procedures of building up the change propagation networks. Within the network, we propose the methodology of simulating change propagations and then present the process of im- plementing the methodologies and the models as a software prototype by using multi- agent based technology.; L’objectif de cette thèse est de fournir des modèles de référence, les méthodes de soutien et des outils qui simulent les change propagations dans un projet de développement de produit (PD) pour aider les prises de décision. Nous établissons d’abord un cadre d’analyse des changes de modéliser le contexte du change apparition et la propagation en prenant en compte les multiples domaines du projet PD simultané- ment. Dans le cadre, nous proposons les modèles conceptuels de change apparition et la propagation qui fournissent une méthode pour identifier les change et propagation et impliquent certaines caractéristiques du change propagations. S’appuyant sur cela, nous vous proposons les procédures de mise en place des réseaux de propagation. Au sein du réseau, nous proposons la méthodologie de simulation de l’évolution propaga- tions, puis de présenter le processus de mise en uvre des méthodologies et des modèles comme un prototype en utilisant la technologie à base multi-agents.