Exhausting lifetime by multitiered reuse with forced circulation in closed-loop manufacturing

In closed-loop manufacturing, the reuse option is adopted to reduce the environmental load by exhausting the lifetimes of products and parts. There are two reasons why the reuse is effective. They are different frequencies of usage of products by users and different lifetimes of parts composing the product. It is, therefore, necessary to make use of these differences properly for effective implementation of the reuse option. For this purpose, this paper proposes a life cycle model that incorporates forced circulation and multitiered reuse. The effectiveness of this model was demonstrated by applying it to the case of photoconductor drum units of copy machines. Units were taken back by compulsion and circulated among other users depending on the volume of copies. When a unit's lifetime was exhausted, it was disassembled and its parts were reused to produce a new unit.