Due to time and budget constraints, the indicators framework has not been tested with the relevant service departments in the metropolitan area. An environmental information system should be built on a variety of conceptual models, and include many different kinds of environmental, economic and societal data and information. The basic functions of an environmental information system are to support the assessment of environmental problems, and to facilitate reporting on these questions to policy-makers and the general public. Sustainability indicators are commonly used to report the state of a system. A conceptual framework for an ecosystem-based information system should consist of hierarchical sets of environmental values, goals and priorities for ecosystems defined at various spatial scales, with sustainability of human activities as an explicit goal and constraint.
Environmental indicators are communication tools between environments and people.
They focus and condense information about complex environments for management, monitoring and reporting uses. The indicator process can take account of social and economic information. Indicators are used to reflect complex systems that may need to be controlled or monitored. They are often derived for Environmental Management System purposes and are based on a life-cycle assessment. EPI's are often developed on a stand-alone basis with no relationship to community needs or sustainability concerns.