LNG Ship Scheduling Optimization via Integrated Constraint Algorithms

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current methods for generating ship schedules in the liquefied natural gas (LNG) industry are inadequate, as they fail to optimize schedules effectively due to limitations in integrating multiple production and storage facilities, varying ship capacities, and contractual complexities, leading to sub-optimal plans and inefficiencies in resource utilization.

Innovation Solution

A computer-implemented method and system that optimizes LNG ship scheduling by defining objectives and constraints, using algorithms to determine optimal decisions, and generating feasible and optimal solutions, while allowing for the prioritization of constraints to minimize violations and maximize economic efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional spreadsheet methods or simple scheduling systems are used, then ease of operation is maintained, but optimization capability and productivity are severely limited

Engineering Contradiction:

Improveschedule optimization efficiencyVSAvoidscheduling system complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The patent replaces manual spreadsheet-based scheduling with an automated computer-implemented optimization system that uses algorithms to generate ship schedules. This substitution of mechanical/manual processes with automated computational methods enables sophisticated optimization while managing complexity through software architecture.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The optimization system automatically generates ship schedules by integrating input data from multiple facilities and applying optimization algorithms without requiring manual intervention for each scheduling decision. The system serves itself by autonomously processing data and generating optimized schedules.

Inventive Principle:

Principle #25Self-service

2Manufacturing precision

If integrated models for capacity planning and ship scheduling are implemented, then manufacturing precision of schedules is improved, but device complexity increases due to multiple iterations required

Engineering Contradiction:

Improveschedule feasibility accuracyVSAvoiditeration process complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent combines capacity planning and ship scheduling into a single integrated optimization model. This merging of previously separate processes allows simultaneous optimization of both aspects, improving schedule feasibility accuracy while reducing the need for multiple iterative adjustments between separate systems.

Inventive Principle:

Principle #5Merging (Combining)

3Productivity

If sophisticated ship scheduling models are used, then productivity is improved, but reliability decreases due to discrepancies in satisfying contractual obligations

Engineering Contradiction:

Improveschedule generation efficiencyVSAvoidcontractual obligation satisfaction

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The optimization system incorporates feedback mechanisms that account for transportation losses such as boil-off and fuel consumption. By integrating these loss calculations into the scheduling model, the system can adjust schedules to ensure contractual obligations are met despite expected losses during transit, thereby improving reliability.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system performs preliminary calculations of transportation losses (boil-off, fuel) when generating ship schedules. By accounting for these losses in advance during the optimization process, the system ensures that schedules are designed to meet contractual delivery requirements, improving reliability before execution.

Inventive Principle:

Principle #10Preliminary action

4Reliability

If multiple hard constraints are enforced to satisfy contractual obligations, then reliability is improved, but adaptability decreases due to reduced flexibility in optimization

Engineering Contradiction:

Improveconstraint satisfactionVSAvoidschedule flexibility

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The optimization system dynamically adjusts constraint enforcement based on the specific scheduling context. Rather than rigidly applying all constraints equally, the system can adaptively prioritize certain constraints over others depending on operational conditions, market opportunities, and contractual requirements, thereby maintaining both reliability and flexibility.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS10878349B2Method of generating an optimized ship schedule to deliver liquefied natural gas

Publication Date: 2020.12.29 EXXONMOBIL UPSTREAM RESEARCH COMPANY(US)

AI summary

A system and method is provided for generating an optimized ship schedule to deliver liquefied natural gas (LNG) from one or more LNG liquefaction terminals to one or more LNG regasification terminals using a fleet of ships. The method involves modeling the ship schedule via an LNG ship scheduling model and a LNG ship rescheduling model to provide optimized decisions for the LNG supply chain. The LNG supply chain includes the one or more LNG liquefaction terminals, the one or more LNG regasification terminals, and the fleet of ships.