Using JIT in a Green Supply Chain
Modeling and Assumptions
Model Symbols and Definitions
Table 1, Table 2 and Table 3 show and defines the symbols, parameters and decision variables of our model.
Table 1. Meaning of the symbols and settings in Numerical Example.
| Symbol | Meaning of the Symbols | Settings in Numerical Example |
|---|---|---|
| m | Manufacturer | 4 |
| s | Supplier | 1 |
| w | DC warehouse | 1 |
| r | Retailer | 1 |
| c | Packaging materials | |
| g | Merchants | |
| TM | Utilize the model of returning vehicle in the supply chain | 1: Recycling packaging materials 2: Transport goods to upstream suppliers |
| n | The planning period | 120 |
| a | Number of suppliers, a = 1, …a | 4 |
| b | The types of merchandise offered by the supplier, b = 1, …b | 5 |
| S | Start ordering time of merchants |
Table 2. Meaning of the Parameters.
| Parameter | Meaning of the Parameters: |
|---|---|
| PSM | Unit cost to the supplier for purchasing products from the manufacturer |
| PWS | Unit cost to the DC warehouse for purchasing products from the supplier |
| PRW | Unit cost to the retailer for purchasing products from the DC warehouse |
| PWM | Unit cost to the DC warehouse for purchasing products from the manufacturer |
| PWC | Unit cost to the DC warehouse for purchasing packaging materials |
| TMS | Unit cost from the manufacturer to the supplier |
| TSW | Unit cost from the supplier to the DC warehouse |
| TWR | Unit cost from the DC warehouse to the retailer |
| TRM | Unit cost from the retailer to the manufacturer |
| TMW | Unit cost to ship from the manufacturer to the DC warehouse |
| FG | Unit cost to the producing merchant |
| FC | Unit cost of producing packaging materials |
| IW | Unit cost of inventory for the DC warehouse |
| IM | Unit cost of inventory for the manufacturer |
| QG | The ordering quantity of goods |
| MIPG | The maximum inventory in the production of goods |
| MADG | The maximum annual demand for goods |
| OCG | Order cycle time |
| LTG | Lead time of purchasing goods |
| SSDG | Safety stock with demand fluctuations for goods |
| SSLTG | Safety stock with lead time fluctuations of purchasing goods |
| OHG | On hand inventory |
| OOG | On-order inventory |
| EMS | Unit carbon emissions as a result of transportation from the manufacturer to the supplier |
| ESW | Unit carbon emissions as a result of transportation from the supplier to the DC warehouse |
| EWR | Unit carbon emissions as a result of transportation from the DC warehouse to the retailer |
| ERM | Unit carbon emissions as a result of transportation from the DC warehouse to the retailer |
| EMW | Unit carbon emissions as a result of transportation from the manufacturer to the DC warehouse |
| ECP | Unit carbon emissions as a result of producing packaging materials at the manufacturing plant |
Table 3. Meaning of the Strategic-Decision Variable.
| Strategic-Decision Variable | Meaning of the Strategic-Decision Variable |
|---|---|
 |
To determine whether or not to ship product B from manufacturer A, on the nth day of the TM case. |