The study of production and inventory policy of manufacturing/remanufacturing environment in a closed-loop supply chain

Figures & data

Figure 1 Hybrid inventory system with manufacturing and remanufacturing (and with or without a disposal option for returned remanufacturing items).

Figure 2 Framework of simulation system.

Figure 3 The remanufacturing processes within the supply chain.

Figure 4 The remanufactured process for the case study.

Table 1 Definition of the parameters and variables in the model.

	Demand number of an order, 3/order
	Assembly time
	Assembly cost ($100/unit)
	Total assembly cost
	Test time (5 min/unit)
	Test cost ($10/h)
	Total test cost
	Yield rate of remanufactured product (5%)
	Maintenance time (5 min/unit)
	Maintenance unit cost ($50/unit)
	Total maintenance cost
	Packaging time (3 min/unit)
	Packaging unit cost ($50)
	Total packaging cost
	Unit cost of new product ($120/unit)
	Total cost of new product
	Unit inventory cost of new materials/parts
	Inventory cost of new products ($0.2857/day)
	Total cost of new products
	Total transportation cost ($100/order)
	Reorder point of new products inventory (100)
	Order number of new products (200)
	Order lead time of new products (1.5 days)
	Reorder point of new materials/parts inventory (100)
	Order number of new materials/parts (200)
	Order lead time of new materials/parts
	Disassembly time
	Disassembly unit cost ($15/min)
	Total disassembly cost
	Cleaning unit cost ($15/number)
	Total cleaning cost
	Unit inventory cost of reused materials/parts ($0.2857/day)
	Total inventory cost of reused materials/parts
	Unit cost of waste disposal ($20/batch)
	TW disposal cost
	Reassembly–disassembly point of reused materials/ parts inventory (50)
	Disassembly number of recycling products (100)
	Unit cost of recycling old products ($100/number)
	Total recycling cost
	Unit inventory cost of recycling products ($0.2857/day)

Table 2 The data of the case study.

Variables		Simulation level
RCR	R1: 205/week	R1: (L, M, H) = (0.0171, 0.0341, 0.0682)	Exponential distribution (day/unit). How long can one recycle a used product?
	R2: 68/week	R2: (L, M, H) = (0.0515, 0.1029, 0.2058)
	R3: 120/week	R3: (L, M, H) = (0.0292, 0.0583, 0.1166)
DR	C1: 15/day	C1: (L, M, H) = (0.0333, 0.0666, 0.1332)	Exponential distribution (order/day). How long can one get an order?
	C2: 8/day	C2: (L, M, H) = (0.0625, 0.1250, 0.2500)
	C3: 10/day	C3: (L, M, H) = (0.0050, 0.1000, 0.0200)
RUR	40∼80%	(L, M, H) = (0.3, 0.5, 0.7)	The usage rate of remanufactured rate.

Table 3 Comparison for different resource recovery operations.

	Level test of equal variables		t-Test of equal averages
Performance index	F-test	Significance	t	Freedom	Significance (two tailed)
CT	1.092	0.297*	− 2.667	160	0.008**
PRR	17.310	0.000*	− 13.111	135.855	0.000**
AW	0.009	0.926*	0.036	160	0.971**
TCR	32.296	0.000*	4.396	134.741	0.000**
*Mean at α = 0.05 significant level, there was significant difference among the variables (the variables were not assumed as equal).
**Mean at α = 0.017 significant level, there was significant difference between different resource recovery operations.