An eco-industrial park is a set of businesses that share resources in order to increase profitability and reduce environmental impact. The implementation of eco-industrial parks may significantly contribute to the creation of a sustainable economy. Despite this prospect, the actual development of eco-industrial parks is challenging, as a variety of factors must be considered. Not only technical, economic, and environmental factors are relevant but numerous stakeholder relationships as well, such as between firms, governmental bodies, and local communities. This paper presents a conceptual framework that is used to capture these diverse aspects and the relationships between them. The Unified Modeling Language (UML) is used for modeling its concepts and relationships. First, based on a literature survey, relevant concepts of eco-industrial parks are identified. One central concept is "industrial symbiosis". A novel value-based interpretation of industrial symbiosis is presented. Second, the park's economic, local and regional development context, as well as its internal technical components and their relationships are modeled. Finally, the framework is used for modeling a concrete ecoindustrial park, in this case part of the Kalundborg eco-industrial park.
BACKGROUND ECO-INDUSTRIAL PARKSAn eco-industrial park (EIP) is proposed as one approach towards a sustainable economy. Contrary to product or firm-specific sustainability approaches, EIPs have a much larger scope. Their influence stretches over three different levels: the firm, across firms, and regional and global [7]. The analysis of existing parks in China, Denmark, and Finland suggest that EIPs can substantially reduce waste and resource consumption over their life cycle [8]-[13]. Despite the promises of the EIP concept, the large number of unsucessful EIP initiatives in the USA and Europe indicate that planned EIP development is challenging [14]. Some of these challenges are pertinent to large-scale infrastructural projects in general, such as geographic attractiveness and managing complex stakeholder relationships [14], [15; pp.25-28]. Some challenges are specific to EIPs such as the implementation of by-product exchange relationships between EIP participants, called industrial symbiosis. [16; pp.987-988], [14; p.1685]. Current research suggests that initiatives by governmental actors alone, without the support of firms, do not lead to successful EIP development [16]-[19]. Research on EIP development has just recently started. Romero & Ruiz [20] use adaptive complex systems theory for modeling and simulationg EIP operations, integrating economic, environmental, and social aspacts. Romero & Ruiz [21] explore how system dynamics and agent-based modeling can be used for modeling and simulating the evolution of EIPs. Rosa & Beloborodko [22] propose a qualitative decision-support tool for evaluating existing industrial symbiosis. A scoring system is used, which takes geographic proximity, economic, and ecological performance into account. Cao et al. [23] have de...