Background The environmental impact of individual small and medium-sized enterprises (SMEs) cannot easily be decreased. Many SMEs do not have the critical size or capacity, nor the necessary resources to develop sustainable management. However, by collectively organising the flow of energy and matter at the level of an industrial estate, SMEs can achieve economies of scale and degrees of effectiveness in their environmental management that exceed those attainable through the separate efforts of individual companies. Industrial ecology seeks to form links between neighbouring companies to convert enterprises’ by-products and wastes into valuable resources for their neighbouring companies. Objectives The S.M.I.G.I.N. project aimed to promote sustainable management within seven economic activity estates, by implementing common solutions to the environmental problems shared by the SMEs. The objective was to organise key environmental and industrial issues at the estate level, such as: waste collection; flows of people, matter and energy; landscaping; and wastewater discharges. The intention was thus to identify more sustainable solutions, and at lower cost, thanks to potential scale-savings. These common solutions would deliver economic and environmental benefits that are greater than the savings that each company would realise from optimizing only its individual performance. The project sought to set an example of interactive governance and industrial networking. Results The S.M.I.G.I.N. project demonstrated how an industrial association or a public-sector institution can help catalyse collective action by companies established in the same industrial park towards better waste management and reduced waste generation, a more efficient use of energy, eco-landscape management and better use of transport. It showed how leadership can help companies reduce their environmental impact while at the same time reducing costs and/or improving their working environment. The project started by developing technical tools for collective management of an economic-activity estate. The team elaborated a methodological guide to developing and implementing an action plan, based on diagnoses of the companies within an estate. A series of action sheets were based around the four themes of waste, mobility, eco-landscaping and energy. To support the guide, they collated an inventory of good practices into an accessible database and developed a collective-management technical guide setting out issues such as the factors that determine success or failure and relevant legal obligations. They also created a toolbox with posters to be displayed within companies, templates of contracts, models of invitations to tender, survey forms and communication material. The methodology was implemented on seven economic-activity parks: five in Wallonia (Saintes, Nivelles Sud, Crealys, Waremme, Courcelles and Geers); and two in France in the Valenciennois region (Sars et Rosieres, and Aérodromme). Saintes and Nivelles Sud were used in a first demonstration cycle, followed by the other five. Diagnoses were conducted of individual companies before identification of collective solutions. The main actions implemented were: Measures to reduce car usage, including the establishment or improvement of shuttles from the parks to train stations and the promotion of both these services and car pooling; Collective management of waste e.g. streaming waste flows of 15 companies at Saintes; Recycling of ink cartridge; Valorisation of pallets between companies ; and Collective awareness-raising efforts around the management of green spaces, waste sorting and energy saving.The project supported studies of the possibility of introducing shared photovoltaic and windmill technologies on estates, energy-efficient building construction and the collective management potential of green spaces and waste through a common service provider. It also promoted the biogas project of the Haut-Geer. Although many environmental benefits will take time to be realised, the project demonstrated the feasibility of common management approaches on industrial parks. It has disseminated this information at Walloon and international level and made its support tools available on the website: www.econetwork.eu Further information on the project can be found in the project's layman report and After-LIFE Communication Plan (see "Read more" section).