The activities of the Fondazione ENI Enrico Mattei cover a broad spectrum of research topics, ranging from economics to engineering, from environmen­ tal management at the industry or regional level to basic mathematical model­ ling research. It is the combination of the activities on these last two topics that led the Fondazione to organise, with the University of Geneva, a work­ shop where operation research tools were designed with the aim to provide national and local policy makers with appropriate analytical and policy instru­ ments for environmental management. In the recent past, attention has often been devoted to global environmen­ tal issues in which the level of policy making is either international, through multi-country agreements on emission control, or national, when environ­ mental policies are designed to control domestic pollution. Many environ­ mental problems, however, have a local or regional dimension. Even when their dimension is global, e. g. in the case of the greenhouse gas effect, relevant decisions on emission control, such as the adoption of energy saving utilities, are taken at the local level. In many countries, the current legislation imposes the local authorities to prepare plans and adopt measures to control energy consumption or to reduce waste of natural resources. It is therefore important to analyze the way in which local or regional authorities optimise their environmental management.