How many times to remanufacture?

A common finding in inventory models for reverse logistics found in the literature, from the earliest to the most recent work, is that the inventory policy shifts between two extremes, i.e., ‘dispose all’ or ‘recover all’. These models also share a common and unrealistic assumption that an item can be recovered indefinitely. Material degrades in the process of recycling losing some of its mass and quality making the option of ‘multiple recovery’ somewhat infeasible. This paper develops a model where an item is recovered a finite number of times. A mathematical expression is developed that estimates the number of recovery times, which is later incorporated into two prominent models from the literature to compare the behaviour of these models with different recovery assumptions. The results suggest that as the number of times an item is recovered increases, the percentage of available used units that are recoverable plateaus. The results also suggest that there is an optimal number of times to recover a product that balances the investment and remanufacturing costs. The study also found that as the percentage of used units collected increases, the significance of ignoring the finite remanufacturing case becomes more important.