For most of the species's existence, humans lived in small foraging bands that had little material surplus and therefore enjoyed a relatively egalitarian existence.

Most metal and plastic parts are designed to be manufactured, which means they can be clunky and contain material surplus to the part's function but necessary for making it.

We can use this system to analyze the status of different material surplus and deficiency , control the dynamic material reserve in reason , avoid the material's overstock or the material's scarcity .