Push and pull disassembly quantity models in a reverse supply chain: the case of an automobile disassembly system in Korea

ABSTRACT

This paper considers the problem of deciding disassembly order quantity in a disassembly system. Returned end-of-use/life (EOL) products are disassembled to retrieve reusable parts sold to secondary markets. For the problem, we suggest novel push and pull disassembly policy models by extending reverse economic order quantity models. The objective of the models is to minimise the costs of the disassembly setup, the disassembly operations and inventory holding, the scrapping of non-reusable parts, and backorder. We develop optimal equations and algorithms for the models and perform a case study of Korean automobile disassembly systems. We then conduct a series of sensitivity analyses based on real-world and reliable data and discuss possible applications of the push and pull policies. The results show that the pull policy gives better in terms of the total cost while the push policy is less insensitive to the disassembly setup cost.

KEYWORDS:

• Reverse supply chain
• Deterministic inventory control
• Economic order quantity
• Disassembly system
• Push and pull policies

Disclosure statement

No potential conflict of interest was reported by the author(s).

Notes

1 This is consistent with effects of divergence characteristics of a disassembly system discussed in Kim et al. (2007). The effects can be stated as follows. First, a disassembly lot-sizing problem cannot be solved using the well-known zero inventory property. This implies that ordinary lot-sizing algorithms cannot be applied to solve the disassembly lot-sizing problem. Second, a disassembly process indispensably results in surplus inventories of disassembled parts. The existence of the indispensable-surplus inventories is one of the unique aspects of disassembly systems compared with assembly systems.

2 It is noteworthy that the optimal inventory target level may not be attainable when the disposal option is not considered (Fleishmann et al., 1997). Because every disassembly process may lead to increase in average inventory levels of parts due to occurrence of their surplus inventories, the inventory level of each part may not be maintained at a certain level.

3 The inventory flow in case of $r\ge \overline{d}$ is the same as in Figure 13. Detail explanation on how to calculate the inventory holding cost of parts is given with Figure 14.

4 It should be noted that a pull disassembly system cannot continue to retrieve parts from a certain point of time when the return rate is too low. That is, no disassembly schedule cannot be obtained if $Q{\overline{d}}^{-1}(1-{\rho }^N)/(1-\rho {)}_{N\to \mathrm{\infty }}$ less than 1 as discussed in Section 5.2. Thus, no disassembly schedule at 70% and 75% of the return rate under the low return case can be obtained as depicted in Figure 8(a) and Figure 12(a).

Additional information

Funding

This work was supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea (NRF-2017S1A5A2A01024245).