The SIGMA technology, a patented new concept for uranium enrichment based on the well-known gaseous diffusion (GD) method, has been developed by the Comisión Nacional de Energia Atómica in Argentina to be an alternative to compete in the uranium enrichment market. The SIGMA engineering approach stands on the integration of several GD stages in one module, with all the stages sharing one single multiflux compressor, one vessel, and a gas turbine. This arrangement, together with the use of the double-diffuser cascade configuration to increase the separative gain, leads to a breakthrough in the capital cost structure of the GD technology and a significant reduction in the energetic and operation costs. With the SIGMA concept, a leveled separative work unit cost that could be almost half the price of the present enrichment market level can be achieved. The SIGMA technology has also been conceived to incorporate proliferation-resistant features, and it has a very small overall proliferation risk. In this work we present the main features of the SIGMA technology, and we formulate a calculation scheme for the overall design analysis. We present some of the results of this investigation, including the SIGMA scale economy, and its comparison with others enrichment technologies.