Two dimensions to the integration of plans may be distinguished: ensuring a relationship between strategic plans and medium-range plans, and between medium-range plans and short-range plans; and ensuring a relationship between all the plans concerned with a particular time frame.
This strategy features in the framework of Agenda 21 as formulated at UNCED (Rio de Janeiro, 1992), now coordinated by the United Nations Commission on Sustainable Development and implemented through national and local authorities. In the context of integrating environment and development in decision-making, Agenda 21 recommends adopting flexible and integrative planning approaches that allow the consideration of multiple goals and enable adjustment of changing needs. Integration of plans is facilitated by developing both quantitative and qualitative plans, thus permitting cross-references among functions, interrelating levels of planning, and providing cross-checks for evaluations. Numerous methods of integrating plans exist, but the most universally used basis for translating strategic plans into actions is a budgeting, or cost-benefit, system. Within the context of sustainable development, integrative area approaches at the ecosystem or watershed level can assist in this approach.