Implementation of eco-design for complex industrial systems: from scenario-based LCA to the definition of a portfolio of eco-innovative R&D projects

Summary Faced with the emergence of environmental problems resulting from human activities, ecodesign aims to offer a satisfactory response in the field of product and service design. However, when the products considered become complex industrial systems, characterized by a large number of components and subsystems, an extremely long and uncertain life cycle, or complex interactions with their geographical and industrial environment, an obvious lack of methodologies and tools is felt. This change of scale brings indeed different constraints both in the assessment of environmental impacts generated during the life cycle of the system (management and quality of data, level of detail of the study compared to the available resources...) and in the identification of appropriate responses (management of multidisciplinarity and available resources, training of actors, inclusion in a context of very upstream R&D...). This thesis aims to develop a methodology for the implementation of an eco-design approach for complex industrial systems. A general methodology is first proposed, based on a DMAIC process (Define, Measure, Analyse, Improve, Control). This methodology allows to define in a formalized way the framework of the approach (objectives, resources, perimeter, phasing...) and to rigorously accompany the ecodesign approach on the considered system. A first step of environmental assessment based on the Life Cycle Assessment (LCA) at a high systemic level is thus carried out. Given the complexity of the life cycle considered and the variability of operation of an industrial system from one site to another, a scenario-based approach is proposed in order to quickly grasp the possible extent of environmental impacts. The operating scenarios are defined using the SRI (Stranford Research Institute) matrix and include many elements rarely addressed in LCA, such as preventive and corrective maintenance, subsystem upgrades, and modulation of the system's life cycle according to the economic context. At the end of this LCA, the main impacting items of the system's life cycle are known and allow to undertake the second part of the eco-design approach focused on environmental improvement. A multidisciplinary working group is brought together during a creativity session centered around the eco-design strategy wheel (or Brezet wheel), an eco-innovation tool that requires few resources and little environmental expertise. The ideas generated in creativity are then processed through three successive filters, which allow: (1) to pre-select the best projects and to deepen them. (2) to build a portfolio of R&D projects using a multi-criteria approach that evaluates their environmental performance, but also their technical and economic performance and their value creation for customers. (3) to control the balance of the portfolio according to the company's strategy and the diversity of the projects considered (short/medium/long term aspects, systemic level considered...). All the work has been applied and validated at Alstom Grid on electrical conversion substations used in the primary aluminium industry. The deployment of the methodology has allowed to initiate a solid eco-design approach recognized by the company and to generate a portfolio of 9 eco-innovative R&D projects that will be implemented in the coming months.