# A Cost-Optimized Model for Dynamic Port Hinterland
## 3 Methodology
### Methodological Proposal
#### 3.2.1 Total Transportation Cost (TTC)  
The concept of Total Transport Cost (\(TTC\)) in international logistics has evolved significantly since its initial formulation by [PERSON] et al. [24]. In the context of FOB (Free On Board) Incoterms, \(TTC\) encompasses all transport-related expenses from the origin port to the final destination point. This comprehensive cost metric includes ocean freight, port management, customs procedures, documentation, and inland transportation, reflecting the complex nature of global supply chains [1].  
Subsequent studies by [PERSON] et al. [68] and [PERSON] et al. [77] have expanded this framework to include environmental costs and risk adjustments, respectively. Building upon these advancements, we can delineate the components of \(TTC\) as follows:  
1. Freight Cost (\(FC\)): Represents the ocean freightage, i.e., the cost of maritime transport between origin and destination ports. [PERSON] et al. highlight the impact of vessel size and fuel prices on this component [43].  
Figure 1: Scheme of contributions to \(TLC\): \(TTC\), \(WHC\), and \(TMC\). Note that any transport mode can be used, although only train and truck are shown. Source: Own elaboration.  
2. Freight Service Costs (_FSC_): Encompasses ancillary costs associated with freight, including insurance, bunker adjustment factor (BAF), and currency adjustment factor (CAF). The volatility of these factors, particularly in light of geopolitical events and environmental regulations, has been examined by [PERSON] and [PERSON] [67].
3. Port Management Cost (_PMC_): Covers expenses related to port operations, including terminal handling charges, storage fees, and port taxes. [PERSON] et al. analyzed the efficiency of port operations and its impact on these costs [42].
4. Border Management Cost (_BMC_): Includes costs associated with customs procedures and inspections. The implementation of blockchain technology in customs processes and its potential to reduce these costs has been explored by [PERSON] et al. [78].
5. Port-to-Warehouse Transport Cost (_PWTC_): This represents the cost of inland transportation from the destination port to an intermediate warehouse. The choice of transport mode for this leg can significantly impact overall costs and has been the subject of optimization studies [79].
6. Transport Distribution Cost (_TDC_): Covers the expenses for transporting goods from the intermediate warehouse to the final destination. Recent research has focused on last-mile delivery optimization in this context [65]. Incorporating these components, Total Transport Cost (_TTC_) can be expressed as: \[TC=FC+FSC+PMC+BMC+PWTC+TDC.\] (4)  
This formulation, while comprehensive, is increasingly being augmented to reflect emerging concerns in global logistics. For instance, [PERSON] et al. [69] propose the inclusion of a carbon cost component (_CC_) to account for emissions throughout the transport chain:  
\[TTC=FC+FSC+PMC+BMC+PWTC+TDC+CC, \tag{5}\]  
where _CC_ represents the monetary value of carbon emissions associated with the entire transport process, typically calculated based on carbon pricing mechanisms or regulatory compliance costs.  
Digital technologies, particularly artificial intelligence and machine learning, are transforming cost calculation and optimization methodologies, enabling real-time routing adjustments and improved efficiency [66]. While the fundamental _TTC_ structure remains valid, future research must develop adaptive models that address modern supply chain complexities, incorporating sustainability, technological advancement, and network resilience considerations.