As we move towards the 21st century, new demands and requirements on the airline industry will continue to dictate the introduction of many new systems, designs and concepts on the airplanes. In line with these developments, there will also be extensive use of software given its potential, flexibility and benefits. Software represents an important aspect of a system's operation - often, processing information, calculating, monitoring, deciding and giving instructions to be carried out.A successful application will be beneficial to the airplane and the airline's operation. On the other hand, the improper and uncontrolled usage of software will lead to adverse effects. Consequently, it is important to draw from the present accumulated experience and apply lessons learned from in-service operations to avoid any undesirable consequences, and to ensure a profitable application.