Conception complexe et ingénierie système.

S'il est une tendance admise en matière de dynamique technique de longue période, c'est bien celle de la complication croissante des « objets techniques » [SIM 58] voulus, conçus, produits et utilisés par l'Homme. Pour s'en convaincre, il suffit de procéder à une comparaison facile et de mettre en rapport une plaque de métal - objet banal du XIX° siècle - avec un téléphone portable – objet banal de notre époque - de même dimension et masse. Il ne fait alors aucun doute que celui-ci répond à plus nombreuses fonctions que celle-là. Il permet en effet de communiquer des messages par la voix, l'écrit ou l'image, de photographier, de filmer, de jouer, d'avoir l'heure, de gérer ses rendez-vous, etc., si bien, d'ailleurs, que sa compréhension par l'utilisateur relève de plus en plus du pensum [MOR 07]. Pour assurer toutes ses fonctions, il intègre de nombreux composants, matériels et logiciels, relevant, qui plus est, de domaines techniques et scientifiques éloignés : télécommunications, électronique, énergie, traitement du signal, logiciel enfoui et interface homme-machine, etc. Du fait de cette densité fonctionnelle particulièrement élevée, il ne peut donc pas se comprendre comme un simple composant, mais comme une véritable architecture multiphysique. Il exhibe aussi différents comportements : il répond aux commandes venant de l'utilisateur lorsque celui-ci appuie sur ses touches ou effleure son écran, il cherche les émetteurs les plus proches, il vérifie l'état de la batterie, il vibre ou sonne, etc. Enfin, il est à la fois produit en masse et varié, ce qui suppose un système de production et une chaîne logistique particulièrement compliqués

Propagating product architecture decisions onto the project organization : a comparison between two methods.

International audienceConcepts like product architecture and modularity have been introduced in order to limit the effects of technological change on complex product design. Researchers have highlighted that product architectures and design organizations (projects, teams...) are strongly interrelated. However, little research has analyzed this relationship. System architects and design managers need a method that helps them to simulate the mapping of the product architecture onto the project organization by propagating choices and then assessing alternatives. In this paper, two propagation methods are presented and compared. The first one is based on a fuzzy process, which is proposed by the authors. The second one is based on a matrix approach. Both are applied to define new robotized gearbox architectures. A sensitivity analysis is conducted. It is concluded that in new product development situations or in re-engineering projects, system architects could use these methods in the early design stages to forecast the more appropriate design project organization

Preliminary Hazard Analysis Generation Integrated with Operational Architecture - Application to Automobile

Abstract. We are witnessing evolution of standards (as the functional safety one) and increas-ing of complexity. This implies to perform safety studies efficiently and earlier in the context of Model-Based System Engineering. So, in this article, we will propose an evolution of the Pre-liminary Hazard Analysis (PHA) method in order to comply with the overall safety require-ments in the automotive domain. To demonstrate its usefulness, we apply this method to an industrial case which concerns the hazard analysis of unintended acceleration of a vehicle

A fuzzy method for propagating functional architecture constraints to physical architecture.

International audienceModular product design has received great attention for about 10 years, but few works have proposed tools to either jointly design the functional and physical architectures or propagate the impact of evolutions from one domain to another. In this paper, we present a new method supporting the product architecture design. In new product development situations or in reengineering projects, system architects could use this method in the early design stages to predetermine cohesive modules and integrative elements and to simulate a domain architecture by propagating architecture choices from another domain. To illustrate our approach, we present an industrial case study concerning the design of a new automobile powertrain

Preliminary hazard analysis generation integrated with operational architecture - application to automobile

International audienceWe are witnessing evolution of standards (as the functional safety one) and increasing of complexity. This implies to perform safety studies efficiently and earlier in the context of Model-Based System Engineering. So, in this article, we will propose an evolution of the Preliminary Hazard Analysis (PHA) method in order to comply with the overall safety requirements in the automotive domain. To demonstrate its usefulness, we apply this method to an industrial case which concerns the hazard analysis of unintended acceleration of a vehicle

Operational and system hazard analysis in a safe systems requirement engineering process - Application to automotive industry

International audienceAutomotive engineers have to meet evolving customer expectations, particularly growing concerns for safety, by introducing new sophisticated devices like Line Keeping Assistance, Collision Mitigation Braking System or Pedestrian Detection. These devices are composed of electrical components. They are likely to be subject to failures that may impact automobile safety, which means the safety of the vehicle occupants or pedestrians. Recent standards like ISO 26262 aim at mitigating these safety problems. Automobile engineers must prove that they perform safety studies along the design process. Meanwhile, they have to cope with other changes in their engineering practices. Due to the goals of verifying the satisfaction of all requirements, the design offices have introduced new practices based on Systems Engineering (SE) which are based on models. SE tools or processes are based on a functional approach of the system in which dysfunctional aspects are missing. Thus, there is a need to integrate the safety domain into the SE framework in order to improve safety studies and the collaboration between systems engineers and safety specialists. This paper analyzes this issue by focusing on the definition of high-level (or vehicle-level) safety requirements. It proposes a Safe Systems Requirement Engineering Process and a method named Operational and System Hazard Analysis (O&SHA) that helps to specify the high-level safety requirements (called safety goals in ISO 26262). It is based on a Model-Based Systems Engineering approach (MBSE) which integrates safety aspects. The added value of the proposed method is illustrated by applying it to two case studies

Towards a safe systems engineering

International audienceFaced with the increasing complexity of systems, model-based system engineering relies on SysML, one of the recognized languages for systems modeling. In the case of the automotive industry, the introduction of model-based systems engineering in the design process is considered as an efficient way to improve design performance and to master new regulations such as ISO 26262 (ISO 2009) concerning functional safety of automotive systems. Although research work exists on model-based safety assessments (see Cressent et al. 2012; Belmonte and Soubiran 2012), there remains a lack of an approach on integrating system engineering and safety analysis, two domains handling their own concepts, models, and methods. In this short article, we are presenting two types of approaches

Definition and verification of functional safety concepts for the definition of safe logical architectures

International audienceEvolving customer expectations, particularly growing concerns for safety, and the development of autonomous vehicles imply the development of many interconnected functions. To meet the expectations of system performances and to respect safety standards like ISO 26262, systems engineering and safety analysis have to be better integrated. In this paper we propose a conceptual framework and a method to define and verify the functional view of the logical architectures from a safety point of view