For anyone considering a job in computer science, the life cycle of systems development is one of the many essential concepts required for a successful career. Patrick Leyseele Many different life cycles are associated with computer systems, including the development, testing, deployment, maintenance and management phases of a computer system. It is important to note that each of these lifecycle stages and activities at each stage are supported by a number of systems engineering and / or management processes. The overall objective is to ensure that computer systems are designed and implemented according to the results established at the beginning of the system's life cycle.