Systems engineers design, develop, and improve engineering systems. Systems engineers are responsible for the proper functioning of the entire system. ... They are involved in research and design, manufacturing, repair, maintenance and marketing. Modern engineering systems are extensive and complex. They include telecommunications networks, defense systems, air traffic control systems, and manufacturing production plants. All this is built with basic components connected with greater or lesser strength. Systems engineers are responsible for the proper functioning of the entire system. They are involved in research and design, manufacturing, repair, maintenance, and marketing. Systems engineering is not only about knowledge of the various areas of engineering, but about making systems work taking into account all the factors involved. These include specifications and objectives, the development of systems over time, the processes and methods involved, as well as economic, safety, quality and environmental considerations. They have to write reports to record the necessary resources, including personnel, machinery, technology and finances.