among the elements considered are presented in both current and potential situations. Simulation and modelling Simulation and modelling are computer-based tools developed to represent reality. They are widely used to analyse behaviours and to understand processes. Models allow demonstration of past changes as well as the examination of various transformations and their impact on each other and other considered factors. They can help to understand the connections between factors and events and to examine their dynamics. Simulation is a process that represents a structure and change of a system. In simulation some aspects of reality are duplicated or reproduced, usually within the model. The main purpose of simulation is to discern what would really happen in the real world if certain conditions, imitated by the model, developed. Although modelling and simulation became even more popular with the development of computing technology, application of these techniques have certain limits. Models represent a simplification of a system that is being examined; therefore the results need to be carefully considered. As the complexity of real systems increases models need to be more and more complex to represent the reality most accurately. In result, they may become increasingly difficult to understand and to be operated. Their complex nature can cause problems with using and managing results. As models constitute a simpler version of reality, certain factors can be omitted, and in consequence can lead to mistakes. Such mistakes are not easy to be found and corrected. Social network analysis Social network analysis (also sometimes called network theory) has emerged as a key technique in modern sociology, anthropology, social psychology and organizational studies, as well as a popular topic of speculation and study. Research in a number of academic fields have demonstrated that social networks operate on many levels, from families up to the level of nations, and play a critical role in determining the way problems are solved, organizations are run, and the degree to which individuals succeed in achieving their goals. Systems engineering An interdisciplinary approach to engineering systems that is inherently complex, since the behavior of and interaction among system components is not always well defined. Defining and characterizing such systems and subsystems, and the interactions among them, is the primary aim of systems engineering. On very large programs, a systems architect may be designated to serve as an interface between the user/sponsor and systems engineer. RADM Grace Hopper, USNR was quoted