This article was originally published in the \"SwitchasiaMAG\", winter 2016/17; tinyurl.com/jf722ll   The concept of closed-loop production was very popular in Vietnam during the 20th Century, especially in the agricultural sector. At that time, the Vườn (Garden) – Ao (Pond) – Chuồng (Cage) farming model used waste from one activity as input for another activity. For example, organic waste from growing vegetables, such as damaged vegetables, old leaves, etc., was used as animal feed for fish in a pond or for poultry and livestock living in an enclosure (cage). Nowadays, with all the profound economic, social and cultural changes, Vietnam has been developing away from a low income agricultural economy to become one of the most active processing service providers in the...