The civilian/commercial market in the field of communications and information has nowadays a fulminate evolution. This evolution is based on satisfying the increasing need of a public that is already familiarized with the advantages of the modern technology. The avalanche of the innovations released on the market created also the necessity for interoperability between different providers. This is mainly because the evolution tends to be unitary. Consequently, there emerged manufactures specialised in certain components that can be integrated in different personalised systems. Furthermore, the laws enforced in UE and not only imposed a series of standards helping the interoperability. Those standards define certain technical performances for different products. These imposed performances together with the more performing modern technology made these commercial products (Commercial Of The Shelf – COTS) more and more attractive for the military, especially in the field of communications and information.This paper will present the possibilities of using COTS' products as part of complex military communications systems. Testing and evaluation of such components aims for maintaining the tactical and technical characteristics of the system while using commercial equipments. As a case study, we will follow the use of small components as FPGA to larger systems as a Satellite. All those regarded through the process of testing and evaluation in order to obtain not only a fail resistant system but also a technical superior one.