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Avionics software is embedded software with legally mandated safety and reliability concerns used in avionics. The main difference between avionic software and conventional embedded software is that the development process is ''required by law'' and is ''optimized for safety.'' It is claimed that the process described below is only slightly slower and more costly (perhaps 15 percent) than the normal ''ad hoc'' processes used for commercial software. Since most software fails because of mistakes, eliminating the mistakes at the earliest possible step is also a relatively inexpensive, reliable way to produce software. In some projects, however, mistakes in the specifications may not be detected until deployment. At that point, they can be very expensive to fix. The basic idea of any software development model is that each step of the design process has outputs called "deliverables." If the deliverables are tested for correctness and fixed, then normal human mistakes can not easily grow into dangerous or expensive problems. Most manufacturers follow the waterfall model to coordinate the design product, but almost all explicitly permit earlier work to be revised. The result is more often closer to a spiral model. For an overview of embedded software see embedded system and software development models. The rest of this article assumes familiarity with that information, and discusses differences between commercial embedded systems and commercial development models. ==General overview== Since most avionics manufacturers see software as a way to add value without adding weight, the importance of embedded software in avionic systems is increasing. Most modern commercial aircraft with auto-pilots use flight computers and so called flight management systems that can fly the aircraft without the pilot's active intervention during certain phases of flight. Also under development or in production are unmanned vehicles: missiles and drones which can take off, cruise and land without airborne pilot intervention. In many of these systems, failure is unacceptable. The reliability of the software running in airborne vehicles (civil or military) is shown by the fact that most air borne accidents occur due to manual errors. Unfortunately reliable software is not necessarily easy to use or intuitive, poor user interface design has been a contributing cause of many aerospace accidents and deaths. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Avionics software」の詳細全文を読む スポンサード リンク
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