3.1. Integrated Evaluation Framework
3.1.1. Overview of the Proposed AHP Framework
To evaluate the effectiveness of introducing blockchain into Physical Internet (PI)-oriented logistics systems, this study develops an Analytic Hierarchy Process (AHP) framework that integrates both quantitative and qualitative criteria. Two coordination approaches are compared:
PI–BC (Blockchain-enabled coordination): a decentralized coordination mechanism in which administrative tasks, information verification, and transaction processing are executed through blockchain infrastructure;
PI–Human (Human-centered coordination): a conventional approach relying on organizational procedures, human judgment, and centralized platforms for coordination and data reconciliation.
The AHP framework follows four structured steps to combine model-based quantitative results with qualitative assessments, as shown in
Figure 1:
Step 1: Define the evaluation goal and alternatives.
The goal is to determine which coordination approach (PI–BC or PI–Human) performs better in a PI-oriented logistics environment.
Step 2: Construct the evaluation hierarchy.
As shown in
Figure 2, three main dimensions—Efficiency (A), Reliability (B), and Safety (C), are adopted, each consisting of multiple sub-criteria derived from expert consultation and the prior literature.
In the proposed framework, the MILP models are intentionally used to quantify the Cost sub-criterion, which can be objectively measured based on network structure, demand, capacity, and coordination mechanisms. Other sub-criteria, such as interoperability, robustness, and transparency, represent organizational and institutional attributes that are difficult to quantify reliably at the adoption stage and therefore are evaluated through expert judgment using AHP. This division allows the framework to combine rigorous optimization for quantifiable performance with structured decision-making for qualitative system attributes.
Step 3: Conduct pairwise comparisons and derive criterion weights.
Experts evaluate the relative importance of criteria using Saaty’s 1–9 scale. Pairwise comparison matrices are constructed, and weights are computed after assessing the consistency.
Step 4: Evaluate alternatives under each sub-criterion and compute the final score.
Quantitative model outputs (e.g., total cost) and qualitative assessments (e.g., transparency, interoperability) are normalized and aggregated with the derived weights to obtain the final performance score of PI–BC and PI–Human.
This stepwise structure provides a transparent and systematic procedure for integrating cost optimization results with qualitative criteria, enabling a balanced evaluation of blockchain adoption within PI-oriented logistics systems.
3.1.2. Evaluation Criteria and Definitions
In the context of the Physical Internet, the evaluation criteria are designed to capture both the economic performance and the coordination quality of logistics networks under different coordination mechanisms. Each criterion reflects a specific dimension that influences the validity of blockchain adoption decisions. Efficiency-related criteria assess whether blockchain-enabled coordination can achieve acceptable operational performance under cost and resource constraints. Reliability-related criteria capture the ability of the coordination mechanism to support stable, interoperable, and resilient network operations in highly interconnected PI environments. Safety-related criteria focus on trust, data integrity, and automation capabilities, which are central to blockchain’s proposed advantages over traditional human-centered coordination. The selection of evaluation criteria was informed by prior studies in logistics performance assessment and blockchain adoption in supply chains.
- (A)
Efficiency
A1 Cost: This is the total operational cost of the logistics network, including transport, environmental, and administrative expenses; the model details are described in
Section 3.2. In the AHP framework, the “Cost” criterion refers to the aggregated monetary-equivalent operational cost obtained from the MILP optimization results. Although the MILP objective function incorporates player-specific preference weights for cost, rigidity, and CO
2 emissions, these weights are used only to generate a comparable network-level cost outcome and do not represent system-level evaluation preferences.
A2 Quality: Service quality, accuracy of delivery, and damage rate.
A3 Labor Force Availability: Ability to ensure adequate and safe human resources.
- (B)
Reliability
B1 Decentralization: Degree to which operations avoid single points of failure.
B2 Interoperability: Ability to integrate with diverse logistics systems and partners.
B3 Robustness: Resilience to disruptions in network operations.
- (C)
Safety
C1 Transparency: Clarity and accessibility of operational and transaction data.
C2 Tamper Resistance: Security against data manipulation and fraud.
C3 Transaction Automation: Extent of smart contract and automated execution capabilities.
3.2. Quantitative Cost Optimization Model
This study considers a multi-company logistics network in which several independent logistics service providers (hereafter referred to as players) must fulfill specific transportation demands between given origin–destination pairs. The network is modeled as a directed graph , where is the set of nodes (e.g., depots, hubs), and is the set of links between nodes. Each link can support one or more transportation modes (e.g., truck, rail), each characterized by its own unit transportation “cost” and maximum capacity.
Each player is associated with the following:
An origin node and destination node ;
A demand volume to be shipped from to ;
A set of weight coefficients () representing the relative importance of transportation cost, rigidity, and CO2 emissions in the player’s objective function. These weights reflect player-specific managerial priorities and are normalized to capture relative preference trade-offs rather than absolute valuations. Their values are specified through scenario-based parameterization to represent different strategic and regulatory contexts.
Common operational constraints for both scenarios include the following:
Demand satisfaction: Each player’s demand must be fully transported from the origin to the destination.
Flow conservation: For intermediate nodes, inflow equals outflow for each player.
Capacity limits: The sum of flows from all players on any link–mode combination cannot exceed its capacity.
The main difference between the PI with Blockchain and PI with Human scenarios lies in the additional cost components (
Table 2):
Organizational coordination costs are assumed to be eliminated due to the trustless and transparent nature of blockchain. Additional blockchain-specific costs are introduced:
System Construction and Maintenance Cost : A fixed cost shared among participants.
On-chain Transaction Fee : Applied per link used by a player, modeled with a binary usage variable.
On-chain Data Storage Cost : Proportional to the transported volume.
- (2)
PI–Human:
In addition to transport, rigidity, and CO2 costs, players incur organizational coordination costs to manage contracts, resolve disputes, and maintain trust among competitive companies in a centralized platform. These costs are proportional to the total flow volume handled for each player.
The cost components introduced in
Table 2 are central to differentiating the two coordination paradigms. The organizational coordination cost (
) in the PI–Human scenario encapsulates expenses related to contract negotiation, manual data reconciliation, dispute resolution, and the maintenance of trust between independent entities. These costs are modeled as proportional to the flow volume, reflecting the increased administrative effort with higher transaction intensity. In contrast, the PI–BC scenario assumes that these human-centric coordination costs are largely eliminated, as blockchain’s core features, decentralized consensus, and immutable records, automate trust and verification. This is the fundamental premise behind the “coordination cost removed” logic. However, this elimination is replaced by technology-specific costs. The system construction and maintenance cost (
) represents the fixed investment in blockchain infrastructure. The on-chain transaction fee (
) is a variable cost incurred for each state-changing operation on the blockchain, such as recording a shipment event. We model it per edge-mode-player combination to capture the granularity of logistics transactions. The on-chain data storage cost (
) accounts for the expense of storing persistent data on the distributed ledger, which is typically more expensive than centralized storage.
In our numerical experiment, the parameter values ( = 500 $, = 1.5 $, = 0.2 $, = 0.5 $) are set to represent a reasonable early-stage adoption scenario. At this stage, blockchain technology costs are noticeably higher than traditional coordination costs, but not so high that blockchain becomes completely impractical. We intentionally chose these values to ensure that both options have their own strengths and weaknesses in the AHP evaluation, creating a meaningful trade-off situation rather than a one-sided result.
The sensitivity analysis that follows (
Section 4.3) will further explore how changes in these key parameters, especially when decision-makers assign different importance to different criteria, affect the relative advantage of each option. This also helps address the uncertainty inherent in these modeling assumptions.
The MILP model formulation is presented as follows.
| Sets |
| Set of nodes in the logistics network. |
| Set of edges representing transportation links. |
| Set of players (logistics participants). |
| Set of available transportation modes on edge . |
| Parameters |
| The demand quantity of player . |
| The start and end nodes for player . |
| The cost per unit transported via mode on edge . |
| The transportation rigidity per unit via mode on edge . |
| The CO2 emission tax per unit via mode on edge . |
| The maximum transportation capacity for mode on edge . |
| The weight coefficients for cost, rigidity, and CO2 emissions for player . |
| Coordination cost per unit flow. |
| Fixed system construction and maintenance cost. |
| On-chain transaction fee per used edge–mode–player combination. |
| On-chain storage cost per unit flow. |
| Decision Variables |
| The amount of goods transported by player via mode on edge |
| Binary variable indicating whether player uses edge with mode (only for PI–BC scenario).
|
| Objective Function |
- (a)
PI–BC ()
- (b)
PI–Human ()
Demand Satisfaction at Origins and Destination
Flow Conservation at Intermediate Nodes
Binary Link Usage (Blockchain scenario)
Non-negativity Conditions
The optimization model integrates transportation cost, operational factors, and coordination mechanisms into a unified framework for comparing PI–BC and PI–Human systems. The objective functions in Equations (1) and (2) capture the fundamental trade-off between operational efficiency and the cost of maintaining coordination. Equation (1) includes blockchain-specific elements such as system development and maintenance fees, on-chain transaction fees, and distributed data storage costs, reflecting the decentralized architecture of PI–BC. In contrast, Equation (2) incorporates organizational coordination cost, which represents the manual reconciliation, negotiation, and trust-building efforts required in the PI–Human scenario.
The constraints in Equations (3) and (4) ensure that each logistics service provider fully satisfies its transportation demand by enforcing flow completion at the origin and destination nodes. Equation (5) imposes flow conservation at intermediate nodes, preventing artificial creation or loss of goods within the network. Capacity limitations are enforced through Equation (6), which restricts the total flow on each link–mode combination to available infrastructure capacity. The binary-continuous linkage in Equation (7) is included only in the PI–BC formulation and associates flow variables with link-usage indicators, enabling the computation of transaction fees based on actual network utilization. Finally, Equations (8) and (9) define non-negativity and integrality conditions for the decision variables.
Together, Equations (1)–(9) form a coherent mathematical representation of logistics network operations under two distinct coordination paradigms. By solving both models under identical demand, cost, and capacity conditions, the framework provides a consistent basis for evaluating the economic and operational implications of adopting blockchain in PI-oriented logistics environments.
The numerical experiment is conducted on a stylized logistics network consisting of 8 nodes and 9 directed links, representing depots and transportation corridors. Each link supports one or more transportation modes, including truck, rail, and ship, with mode-specific cost, emission, and capacity parameters. The network involves 4 logistics players, each with a predefined origin–destination pair. Player demand levels range from 40 to 70 units. Transportation capacities vary by mode, with typical values of 80 units for truck, 60 units for rail, and 72 units for ship. This network configuration allows for multi-modal routing and capacity sharing while remaining computationally tractable for comparative analysis.