The essay offers a general overview of the traditional and innovative methods adopted by public institutions in their administrative action. The traditional methods derive from administrative praxis, whereas the innovative praxis from economic sciences. Social planning utilises a specific empirical methodology and avails itself of a multi-disciplinary approach. Sociology, demography, cultural anthropology, town planning and social policy are the disciplines which provide the most important contribution. Among the different methods takes into consideration, the "estimated need methods" stands out, being that which is the most easily applied by social workers and requires the high availability of funds and a powerful organisational structure. Among the methods derived from economic sciences, the PPBS and the cost-benefit analysis are considered.