In the early days of aviation, maintenance requirements were determined by a few experienced mechanics with assistance from the manufacturer. As the aircraft became more complex through technological advancements, it was recognized that a more sophisticated method of developing maintenance programs was needed.
Consequently, a logic was developed which introduced engineering discipline into maintenance program development. Just as each subsequent aircraft design introduced new enhancements, each revision to the logic for developing maintenance programs provided a somewhat better approach. The latest of these revisions is known as MSG-3.(1)*