Hybrid Quantum-Classical Fault Tree Analysis

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current fault tree analysis methods require significant computational resources and are time-consuming, especially for complex systems, as they need to evaluate and store intermediate results to identify all minimal cut sets that lead to system failures, without an initial search parameter or heuristic.

Innovation Solution

Combining digital computer systems with quantum processing devices, specifically using quantum annealers to identify the smallest minimal cut sets and then using this information to constrain classical solvers to speed up the search for remaining cut sets, thereby reducing computational burden.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If classical exhaustive search methods are used to identify all minimal cut sets, then completeness of fault tree analysis is achieved, but computational time and memory resources increase significantly

Engineering Contradiction:
Improvecompleteness of fault tree analysisVSAvoidcomputational time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The quantum annealer performs preliminary action by identifying the smallest minimal cut sets (lower bound) before the classical solver executes. This preliminary identification of critical small cut sets allows the classical algorithm to be optimized and constrained, reducing the overall computational time while maintaining completeness of the analysis.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The fault tree analysis is segmented into two distinct phases: (1) quantum annealer identifies minimal cut sets of size up to a threshold k, and (2) classical solver identifies remaining cut sets larger than k. This segmentation allows each method to operate in its optimal regime, with quantum handling the combinatorially difficult small cut sets and classical handling the larger ones.

Inventive Principle:
Principle #1Segmentation

2Reliability

If classical exhaustive search methods are used to identify all minimal cut sets, then completeness of fault tree analysis is achieved, but memory resources required to store intermediate results increase

Engineering Contradiction:
Improvecompleteness of fault tree analysisVSAvoidmemory resources
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The analysis is segmented such that the quantum annealer handles identification of small minimal cut sets (size ≤ k) using its quantum memory advantages, while the classical solver handles larger cut sets. This segmentation reduces the peak memory requirements compared to a single classical exhaustive search that must store all intermediate results for all possible cut sets.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The threshold parameter k is introduced to control the division of work between quantum and classical solvers. By adjusting k, the system can optimize the balance between quantum processing load and classical memory requirements, adapting to available computational resources while maintaining analysis completeness.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If quantum annealers are used to identify minimal cut sets, then computational speed is improved, but device complexity increases due to hybrid quantum-classical system

Engineering Contradiction:
Improvecomputational speedVSAvoidsystem architecture
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system merges quantum annealing technology with classical fault tree analysis algorithms into a hybrid architecture. The quantum annealer and classical solver are integrated through a coordinated workflow where quantum identifies small minimal cut sets and classical completes the analysis, achieving speedup while managing complexity through clear division of labor.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

A threshold parameter k serves as an intermediary that mediates between the quantum and classical components. This parameter controls the handoff point where quantum annealing transitions to classical solving, simplifying the interface between the two complex systems and making the hybrid architecture more manageable.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS10796240B2Performing fault tree analysis on quantum computers
Publication Date: 2020.10.06 QC WARE CORP
  • US10796240B2 patent drawing
  • US10796240B2 patent drawing
  • US10796240B2 patent drawing

AI summary

Fault tree analysis is performed using a combination of digital computer systems and quantum processing devices. For example, quantum annealers may be configured to analyze a fault tree for minimal cut sets. The quantum annealer may be particular good at identifying smaller minimal cut sets. Digital computer systems may be used to identify the remaining minimal cut sets. If the quantum annealer identifies one of the minimal cut sets of smallest size (i.e., lowest cardinality), this can be used as a constraint for the digital computer system, thus speeding up its search for other minimal cut sets.