Abstract
A commercial aircraft consists of 3-4 Million parts depending on its type. It is noteworthy that freighter conversions would have significantly fewer parts than the full passenger versions. Components and systems are made up of parts. Assemblies are made up of components. The aircraft, itself is the top assembly which consists of parts, Commercial Off-the-Shelf (COTS), loose-items, standard parts such as fasteners and consumables. The systems such as hydraulic, pneumatic, wire-harness, Environmental Control System (ECS), and others are crucial members of the aircraft. These systems have many interfaces in the cockpit, cabin, or cargo bay. For example, the passenger overhead panel is one of them that is an outlet of the ECS for conditioned airflow and wire-harness for illuminating. As shown in Figure 1 below there are some buttons on this panel which is an interface between complicated systems and passengers.