Abstract
Comparisons of the functions and reliability of man-made and bio-materials were carried out and their life spans and reliability were also discussed. The protection levels of man-made and bio-materials were classified into 20 levels such as the materials themselves, energy consumption and self-protection, based on the materials used in both systems. Although the selection and the passive protection system of man-made goods are superior to those of living bodies, the total reliability of the latter is much better for their active protection and protection against invaders. The lack of these protections reduces the reliability of modern industrial goods. The adaptations by which goods or a living body can be adjusted to circumstances are listed and the short lives of industrial goods are discussed from the viewpoint of the materials used.
