This paper describes the new ISAE manufacturing survey design and its recent reengineering process. Three important goals have been reached: First, the underlying industrial structure for the aggregation of survey results is now based on the up-to-date NACE Rev. 1.1 classification (at the 3-digit level), adapted to take into consideration the structure of the Italian economy. Second, weights used in the aggregation have now been updated to the year 1999. Third, the weighting scheme is now based on a coherent system of firm-size weights, based on a four-stage method in which the firms' employees are used as weights to aggregate the firms' results for the balance of a question in each strata; then results for each strata are aggregated to calculate the total manufacturing, using updated value added weights (coming from an external source, ISTAT). As a consequence, the general quality of the ISAE survey data has strongly improved: Results are now more reliable at an international level and a full comparability between national, regional and firm-size level data is also ensured. Finally, historical data up to 1991 have been re-calculated according to the new aggregation scheme, in order to ensure intertemporal comparability of the data.