Port Quantum Twin: Toshiba and Port of Yokohama Deploy Quantum-Inspired Digital Twin to Streamline Container Flow
December 28, 2021
Background: The Challenge of Modern Port Logistics
As global supply chains grew more strained in 2021, port congestion became a visible chokepoint. Ships waited days for berths. Containers clogged terminals. Truck turnarounds slowed. Ports like Yokohama, Japan’s second-largest, faced immense pressure to modernize operations—especially with container volumes rebounding post-COVID.
Key logistical challenges included:
Container dwell time exceeding targeted windows
Inefficient berth and crane scheduling
Poor yard stacking order, causing excessive reshuffling
Inflexible intermodal transfer planning between trucks and ships
Traditional optimization tools struggled with the NP-hard nature of these problems—especially as variables surged due to unpredictable ship arrivals, labor shortages, and limited yard space. Enter Toshiba’s quantum-inspired computing approach.
Simulated Bifurcation Machine: Quantum Power Without Quantum Hardware
Toshiba’s Simulated Bifurcation Machine (SBM) is a quantum-inspired optimizer that simulates quantum tunneling behavior using high-speed classical computing. Unlike quantum gate computers or annealers, SBM is available today and is already deployed across Toshiba’s logistics and energy optimization clients.
In the Yokohama Port project, SBM powered a dynamic digital twin—a real-time virtual replica of port assets and workflows. This allowed the port’s logistics team to:
Simulate thousands of future scenarios
Re-optimize plans instantly as ship ETAs, crane availability, or weather conditions changed
Perform multi-objective optimization balancing throughput, emissions, and service time
Scope and System Integration
The project focused on three key domains of port operation:
Container Yard Optimization
Improved stacking strategy to reduce reshuffling
Prioritized placement of time-sensitive cargo near transfer lanes
Berth and Crane Scheduling
Dynamic reallocation of berths based on ship size, cargo type, and predicted dwell time
Synchronized crane deployment to minimize idle motion
Intermodal Truck Coordination
Real-time slot booking optimization for outbound trucks
Minimized truck idle time via predictive container readiness estimates
The system was integrated with:
Yokohama Port’s TOS (Terminal Operating System)
Real-time weather and ETA feeds
Trucking company booking portals
AI vision systems for yard monitoring
Digital Twin as a Quantum Optimization Interface
At the heart of the system was the quantum-enhanced digital twin—an interactive simulation environment updated every 5 seconds with:
Container positions
Crane availability
Vessel berthing status
Truck queue metrics
The SBM ran optimization loops continuously, updating optimal decisions for:
Where to place new incoming containers
Which crane to assign to a vessel next
How to assign trucks to lanes and docks for fastest turnarounds
These decisions were visualized via a digital dashboard used by port managers and terminal operators, allowing human override and “what-if” scenario testing.
Key Results from December 2021 Deployment
During the December trial period (12/1–12/21), the system delivered measurable improvements:
Metric
Improvement
Avg. container dwell time
↓ 17.3%
Crane idle movement (non-load lifts)
↓ 22.8%
Truck turnaround time
↓ 19.5%
Yard reshuffle operations
↓ 25.2%
Berth utilization efficiency
↑ 15.1%
Port of Yokohama officials noted smoother traffic flow within the yard, fewer truck delays at gate checkpoints, and reduced overall container handling costs.
Sustainability and Emissions Impact
By improving crane efficiency and reducing unnecessary container reshuffling, the system helped Yokohama Port:
Lower fuel consumption for rubber-tired gantry cranes (RTGs)
Reduce truck idling outside the port perimeter
Increase throughput per hour, improving vessel servicing efficiency
These enhancements aligned with the Ministry of Land, Infrastructure, Transport and Tourism (MLIT)’s Port Decarbonization Roadmap, and earned the pilot project a SmartPort Innovation Award from Japan’s port authority network.
Toshiba’s SBM vs. Traditional Solvers
Traditional solvers like mixed-integer programming (MIP) or rule-based heuristics struggled with the dynamic, multi-layered complexity of port operations—particularly when facing disruptions like late vessel arrivals or typhoon warnings.
Toshiba’s SBM offered:
Near real-time computation (<3 seconds) even with 10,000+ variable configurations
Better handling of constraint-rich environments (e.g., hazardous cargo separation, customs pre-clearance, crane service radius)
Scalability to include future variables such as carbon emissions pricing or AI-driven demand prediction
Collaboration Model and Expansion
The project was a three-way collaboration between:
Toshiba Digital Solutions, providing the optimization engine
Yokohama Port Authority, managing digital infrastructure and data feeds
Yokohama Container Terminal (YCT), handling operations at on-site berths and yards
Following the success of the pilot, Toshiba began discussions with:
Nagoya Port and Kobe Port for regional deployment
Singapore Maritime and Port Authority (MPA) for feasibility assessments
Integration with Japan’s national SmartPort cloud initiative
Global Port Trends and Quantum Adoption
Ports worldwide are beginning to explore quantum and quantum-inspired solutions, including:
Port of Rotterdam: Quantum-safe encryption and logistics scenario modeling
Port of Los Angeles: AI routing simulations with planned quantum trials
Hamburg Port Authority: Research with Fraunhofer on quantum-enhanced berth planning
Yokohama’s SBM-based digital twin is one of the first operational, live-deployed systems using quantum-inspired computing in a major port.
Key Challenges and Lessons Learned
While successful, the pilot surfaced several operational lessons:
Training gaps: Port staff needed extensive upskilling to interpret digital twin insights
Data quality: Inconsistent tagging and GPS lags affected optimization accuracy
Change management: Shifting from rule-of-thumb scheduling to algorithmic decision-making faced initial cultural resistance
Toshiba responded by:
Adding explainability layers to the optimizer (e.g., “Why this crane was assigned here”)
Offering simulations for operators to test their intuition against algorithmic suggestions
Rolling out modular deployments, letting teams adopt optimization gradually
Looking Ahead: Quantum-Enhanced Smart Ports
Building on December 2021’s success, Toshiba and Yokohama Port have outlined next steps:
Extend optimization to energy management, including battery storage and peak-shaving for RTG cranes
Integrate quantum-safe cybersecurity protocols into data sharing between vessels, customs, and yard operations
Add AI forecast layers for weather, cargo demand, and vessel delays to guide preemptive optimizations
The broader vision is to establish a national network of quantum-optimized smart ports, sharing learnings, algorithms, and simulation capabilities across Japan.
Conclusion: Quantum-Inspired Logistics Comes to Shore
The deployment of Toshiba’s SBM system at Yokohama Port represents a pivotal step in the convergence of quantum computing and global logistics. By enhancing berth scheduling, container stacking, and truck flow in one of Asia’s busiest gateways, this initiative proves that quantum-inspired optimization is not just theoretical—it is operational, scalable, and impactful.
As global trade rebounds and port congestion continues, these technologies will become critical in building resilient, efficient, and sustainable maritime supply chains.