Design develops actant systems. Polycentric design disciplines (including service design) are optimized to integrate multiple interacting human actants into the actant systems they develop. In contrast, monocentric design disciplines were optimized for a single human actant.

One exciting aspect of seeing design this way is purely etymological. Human actants in a design system are designated defined roles in the system. They are, as such designees. In design we designate roles both to people and to engineered sub-systems as actants within our systems. Cool!