Table 2.

CE system perspectives for this research.

Authors	Macro-System Perspective/Levels	Meso-System Perspective/Levels	Micro-System Perspective/Levels
Kirchherr et al. (2017) 114	☆Global level ☆National level ☆Industrial structure level	☆Eco-industrial parks level ☆Regional level	☆Product level ☆Company level ☆Customer level
Saidani et al. (2018) 202	☆City level ☆Regional level ☆National level	☆Businesses level ☆Industrial symbiosis	☆Product level ☆Company level ☆Customer level
This research	☆City level ☆Regional level ☆National level ☆Global level	☆Business level ☆Production chain level ☆Industrial symbiosis ☆Eco-industrial parks	☆Material level ☆Component level ☆Product level ☆Customer level