Software engineering changes world culture due to widespread computer use. Electronic mail (E-mail), the World Wide Web and instant messaging allow people to interact in new ways. The software lowers the cost and improves the quality of health services, fire departments, government agencies and other social services. Successful projects which have used software engineering methods include Linux, the space shuttle software, ATMs and more. The SI can be considered as applied to software engineering, ie by means systematic and tool presets, applying them in the most efficient way to obtain optimal results, always looking for targets engineering. It is not just solving problems, but rather taking into account the different solutions, choose the most appropriate.