Concurrent Engineering

Given that most large-scale complex engineering systems need to be simplified and layered before being designed, a hierarchical approach is necessary to ensure a global and structured understanding of the whole system, including involved stakeholders, use cases, and associated requirements. Even though use cases in themselves are quite intuitive, the process around them is a much bigger challenge since it usually varies from one situation to another. The key step in the proposed methodology is the identification of the system dimensions as a mean to organize use cases. In this article, we propose a framework to address the system dimensions by defining useful functional spaces and accordingly classify the scenarios. As a case study, we analyze and model a cooperative intersection safety system using a hierarchical method to represent use cases. The key challenge in enhancing intersection safety is to identify vehicles that have a high potential to be involved in a collision as early as possible and take preventive action thereof. Such a system design and implementation needs an analysis phase during which the system to design and its environment are analyzed and decomposed. This approach simplifies the understanding of the intersection crossing problem by applying transformations that reduce its complexity. It begins with a thorough analysis of accidents at intersections and providing the main characteristics of these accidents. From the type and severity of accident scenarios, a classification of relevant scenarios is made. The proposed methodology establishes a strong and intuitive link between use cases on one hand and requirements and functional architecture on the other. Moreover, coherency is increased as the hierarchy of use cases affects the hierarchy in functional architecture.

In engineering design, capturing customers’ requirements exactly and transforming them into design specifications are vital to designing a quality product. However, the expressions of customer requirements are normally imprecise and ambiguous due to their linguistic origins. There is still a lack of a systematic approach for elaborating these requirements and transforming them from informal to formal. Therefore, this article provides a scenario-based, systematic approach for requirements management in engineering design. The requirements management process is conceptualized as a three-phase model, and scenarios are integrated into this model for elaborating and formally representing the requirements. A case study of a soy milk maker design is also provided to demonstrate the proposed approach.

The integration of environmental concerns into the product design process is not trivial when dealing with complex industrial systems. Actually, environmental assessment methodologies like Life Cycle Assessments reach, in this case, methodological and organisational limits. More generally, the complexity inherent in the design process may put off eco-design initiatives from a lack of organisational management, methods and tools. In this article, we propose a project management methodology to facilitate the integration of eco-design into the design process of complex industrial systems. This methodology is based on continuous improvement and a Define, Measure, Analyse, Improve, Control (DMAIC) process. It is then structured around precise team definition, precise milestones, deliverables and phases. A first stage ensures a reliable environmental assessment of the full system and the identification of environmental improvement projects. A second stage allows the independent execution of the most promising improvement projects. A first application is proposed on the Alstom Grid AC/DC (alternative current/direct current) conversion substations for the aluminium industry. A Life Cycle Assessment has been performed with limited resources and has provided rich findings and promising perspectives. It shows in particular that the best environmental configuration of such a complex industrial system depends on external parameters like the implantation site.

In the normal life span of large enterprises, the strategic management of IT often evolves. Existing services must be replaced with new services without impairing operations. The problem of scheduling such replacement is of critical importance for the success of the operation. We analyze this problem from a quantitative point of view, underlining the trade-off nature of its solutions. We formalize this multiobjective optimization problem as a mathematical programming formulation. We discuss its theoretical properties and show that real-world instances can be solved by standard off-the-shelf tools.

This article addresses the problem of safety evaluation of complex systems. It proposes an original and rigorous approach that integrates safety analysis in system engineering processes. The approach is based on system engineering principles and uses the famous industrial system engineering standard American National Standards Institute/Electronic Industries Alliance 632:1999. The objective is to help designers and safety engineers in safety management of complex systems. For an efficient design, the model-driven design is adopted through the definition of an information model. The system language “System Modeling Language” is used to address requirements definition and their traceability toward the solution and the verification and validation elements. This common language allows sharing information between the different persons involved in the design project like the system engineer and safety engineer.

The article addresses the challenges of software development for current and future parallel computers, which are expected to be dominated by multicore and many-core architectures. Using these multicore processors for cluster systems will create systems with thousands of cores and deep memory hierarchies. To efficiently exploit the tremendous parallelism of these hardware platforms, a new generation of programming methodologies is needed. This article proposes a parallel programming methodology exploiting a task-based representation of application software. For the specification of task-based programs, a coordination language is presented, which uses external variables to express the cooperation between tasks. For the actual execution of a task-based program on a specific parallel architecture, different dynamic scheduling algorithms embedded into an execution environment are introduced. Runtime experiments for complex methods from a numerical analysis are performed on different parallel execution platforms.