## 3 Materials and Methods
### Greenhouse Gas Emissions According to the ISO 14083 Standard  
Energy demand for freight transport is expected to rise due to the continued globalization of trade and SCs [24]. Emissions from transporting items are typically much higher than those associated with holding them in stock. The environmental impact considered in this study is GHG emissions arising from transport activities related to inventory replenishments on the warehouse--DC route according to the ISO 14083 standard.  
Greenhouse gas emissions arising from transport operations are influenced by the delivery route, number, and size of shipments required to fulfill market demand, vehicle type, LF, and environmental and traffic conditions and are proportional to the amount of fuel consumed by a vehicle [69]. This research considers shipments by road freight transportation between the Netherlands city districts of Rotterdam and Amsterdam, with a distance (d) of 73.37 km. Diesel vehicles of EURO 6 emission standard and six different payload capacities (VPC) are being used. Vehicle selection is based on the minimum payload sufficient to deliver the entire order in a single trip, as shown in Table 1. The freight is of the average goods type, with the product unit weight (w) of 5.5 kgs. The volume of goods is not a limiting factor for shipping.  
Methodology for the quantification and reporting of GHG emissions arising from transport chain operations--ISO 14083 standard--is used to determine the emission levels released during transportation related to inventory replenishments required for fulfilling the SC's fill rate based on operational factors and the periodic review inventory system. For this purpose, the EcoTransIT online application was used [70] as one of the tools for the calculation of the environmental impacts of freight transport chains [71; 72]. It enables the calculation of emission data as required by the ISO 14083 standard, meaning Well-to-Wheels or the total GHG emissions, including emissions from the generation of final energy and Tank-to-Wheels or operational emissions caused by operating the vehicle [73].  
\begin{table}
\begin{tabular}{c c c c c c c} \hline
**Vehicle Type** & **\textless{3.5 t}** & **3.5–7.5 t** & **7.5–12 t** & **12–20 t** & **20–26 t** & **26–40 t** \\ \hline Vehicle payload & 1.5 & 3.5 & 6 & 11 & 15 & 26 \\ capacity, VPC & 27.40 & 41.10 & 58.20 & 75.30 & 95.80 & 123.20 \\ \hline \end{tabular}
\end{table}
Table 1: Logistics and cost parameters of the delivery vehicles.  
Total Well-to-Wheels GHG emissions (\(\rm G_{w}\)) emitted during the observed period due to inventory replenishments are calculated according to Equation (6), where \(\rm g_{w}\) represents the Well-to-Wheels GHG emission factor:  
\[\rm G_{W}=F\cdot g_{W}\cdot N_{d} \tag{6}\]  
Total Tank-to-Wheels GHG emissions (\(\rm G_{T}\)) emitted during the observed period due to inventory replenishments are calculated according to Equation (7), where \(\rm g_{T}\) represents the Tank-to-Wheels GHG emission factor:  
\[\rm G_{T}=F\cdot g_{T}\cdot N_{d} \tag{7}\]  
Table 2 shows the research parameters, values, outputs from SEs, symbols, and units used in this paper.