Today the assembly sequence for the products is often carried out manually and its definition, typically, is very expensive, not guaranteeing optimal solutions. Coming up with an efficient assembly sequence is the essential step to improve process productivity and reduces the time and costs related to assembly machines and equipment. The issue related to the assembly sequence of a product depends on the total number of the its components. In particular, the number of the possible sequences can be obtained through the calculus of the factorial of the number of the product components. This work presents an automatic approach intended to define assembly sequences, based on the information regard the contacts and the interferences existing among the components, which is obtained by the assembly CAD model of the product. The level of the information required by this approach allows its implementation at early stages of design, as soon as the layout of the conceptual solution of the product is defined, independently by the method used to model the CAD assembly. The procedure proposed is focused to obtain a reduced number of assembly sequences, guaranteeing that there is at least one feasible assembly sequence among them. The procedure is oriented to iteratively identify independent and important subassemblies into the CAD assembly, then merge them to specific assembling nodes and generate sequences until the whole product is analyzed. After a brief review of current methodologies developed for assembly planning, in this paper, the automated procedure for assembly sequence generation is explained and applied on an example, obtaining feasible solutions.