This article focuses on a key phase of the conceptual design, the synthesis of structural concepts of solution. Several authors have described this phase of Engineering Design. The Function-Behavior-Structure (FBS) is one of these models. This study is based on the combined use of a modified version of Gero’s FBS model and the latest developments of modeling languages for systems engineering. System Modeling Language (SysML) is a general-purpose graphical modeling language for specifying, analyzing, designing, and verifying complex systems. Our development shows how SysML types of diagrams match with our updated vision of the FBS model of conceptual design. The objective of this paper is to present the possibility to use artificial intelligence tools as members of the design team for supporting the synthesis process. The common point of expert systems developed during last decades for the synthesis of conceptual solutions is that their knowledge bases were application dependent. Latest research in the field of Ontology showed the possibility to build knowledge representations in a reusable and shareable manner. This allows the construction of knowledge representation for engineering in a more generic manner and dynamic mapping of the ontology layers. We present here how processing on ontology allows the synthesis of conceptual solutions.

The early evaluation of a proposed function structure for a product and also, the possibility to expose the potential failures related to this provides that the design process can be modeled in its entirety. However, so far there are no existed suitable models for the early phase of design process. This article presents an integrated approach aimed to explore the behaviors of concept designs in the early design phase. The approach is founded on a combination of Petri net, π-numbers, qualitative physics principles and Design Structure Matrix. The final aim is to implement this method on the SysML modeling language to integrate a simulation approach that is initially not standardized in the language. A second interest of the approach is to provide a coherent simulation framework that can be used as a reference to verify the coherency of other simulation models further in the design process.

In product platform development the technology selection issue has seldom been studied. This article tries to fill this gap by introducing an original Technology Selection Method (TSM) to help designers to manage technology selection within the design of a product family. This method is based on technological coverage and functional verification, including the behaviour of the future product family. Practically, the proposed approach uses a multi-objective analysis based on dimensional analysis theory to choose the best technology available. The developed approach has three major points of interest. First, dimensional analysis theory is considered as a specific type of multi-objective optimisation approach which aggregates attributes using a weighting method based on the laws of physics. This manner of viewing dimensional analysis theory provides a scientific coherence to the weighting process which is not obtainable with other multi-objective methods. Second, the principle of similarity included in dimensional analysis theory is extended and allows a range of technologies and range of functions to be compared in a unique design space. Third, the dimensional analysis provides a powerful simulating tool for studying different kinds of behaviours and interactions between attributes. Consequently, dynamic aspects can be analysed and robustness analyses can be performed. The interest of such a method is highlighted through a case study involving a family of small excavators. We suggest that the potential scope of the approach is broad and our aim is to demonstrate the entire scope of the approach in future research.

Comparison and ranking of solutions are central tasks of the design process. Designers have to deal with decisions simultaneously involving multiple criteria. Those criteria are often inconsistent in the sense that they are expressed according to different types of metrics. This means that usual engineering performance indicators are expressed according to physical quantities (i.e. SI system) and indicators such as preference functions can be “measured” by using other type of qualitative metrics. This aspect limits the scientific consistency of design because a coherent scientific framework will at first require the creation of a unified list of fundamental properties. A combined analysis of the measurement theory, the General Design Theory (GDT) and the dimensional analysis theory give an interesting insight in order to create guidelines for establishing a coherent measurement system. This article establishes a list of fundamental requirements. We expect that these guidelines can help engineers and designers to be more aware of the drawbacks linked with the use of wrong comparison procedures and limitations associated with the use of weak measurement scales. This article makes an analysis of the fundamental aspects available in major scientific publications related to comparison, provides a synthesis of these basic concepts and unifies those concepts together from a designing perspective. A practical design methodology using the fundamental results of this article as prerequisites has been implemented by the authors.

International audienceLife cycle considerations and design options are hardly quantitatively taken into consideration during the conceptual design phase. In order to overcome this deficiency, a general theoretical framework is developed in this paper. In this paper design activity is analyzed via topology. At first in the second section, the basic semantic used in this research is defined from an intentional viewpoint. In the third section, we use the axiom 4 of the General Design theory to show that an order exists on the topological spaces. In that perspective, we show the practical interest of a two steps approach- at first a systematic description of the design problem using classifications, followed by the use of dimensional analysis in order to obtain a metric space. Afterwards, using the example of a pressure regulator, we show that the framework helps in generating concepts, simulating the behavior of such concepts and modeling the entire life cycle. In order to model the entire life cycle two proposals are made in this article. The first one consists of adding three new quantities and units to the SI system, for the reason that, engineering design is dealing with the technical performances of the products but also with three other quantities respectively the information, the environmental impact and the monetary quantity. The concept of information is used to measure the three different types of complexity defined in this research respectively the macro-geometrical, micro-geometrical, and material complexity. The unit used to measure these attributes is the Shannon (sh). The environmental impact quantity is measured via the derived quantity called entropy. The unit of entropy is related to four base units respectively M.L2 ·.t−2 .T−1 with respectively M: Mass, L: Length, t: Time and T: Temperature. The monetary quantity is measured using the Euro (€). Theoretical aspects relating to these choices are investigated in this paper. The second original proposal consists of using systematically the dimensional analysis theory in order to ensure the topological transformation from the physical problem into a mathematical one. Moreover dimensional analysis should become a powerful tool for comparing concepts and diminishing the problem complexity. This framework is applied in order to treat respectively the physical, the economical and the environmental aspects associated with the design problem