Neural Network KPI Control for Bottleneck WIP Reduction

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Solution Overview

Problem

Traditional methodologies are inadequate for identifying key factors contributing to cycle time reduction in complex manufacturing processes, such as semiconductor wafer fabrication, where dozens of stages with multiple steps are involved, leading to unreliable results.

Innovation Solution

A system and method that groups tools by similar process steps, collects and analyzes process profile data to calculate key performance indicators (KPIs), uses a neural network model to assess the impact of KPIs on work-in-progress (WIP), and adjusts tool group operations to reduce total WIP, focusing on standard deviation of bottleneck tool groups to improve cycle time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional methodologies (linear programming, computer simulation, queue model) are used to analyze complex manufacturing processes, then the analysis can be performed with simple tools, but the reliability of identifying key cycle time factors deteriorates due to process complexity

Engineering Contradiction:
Improveease of analysisVSAvoidreliability of cycle time factor identification
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces traditional mechanical/mathematical analysis methods (linear programming, queue models, simulation) with an AI-based neural network system. The neural network learns patterns from historical manufacturing data to identify key cycle time factors, substituting conventional analytical mechanics with intelligent computational mechanics that can handle complex, non-linear relationships in semiconductor manufacturing processes.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Adaptability or versatility

If the manufacturing process includes dozens of stages with multiple steps (as in semiconductor wafer fabrication), then the manufacturing capability and product complexity increase, but the difficulty of detecting and measuring key cycle time factors increases

Engineering Contradiction:
Improvemanufacturing process capabilityVSAvoiddifficulty of identifying key cycle time factors
Core Design Contradiction:
Adaptability or versatilityVSDifficulty of detecting and measuring

Solution Approach 1:

The patent introduces an intermediary layer between the complex manufacturing process and the analysis system. The neural network acts as an intermediary that processes raw manufacturing data, extracts relevant features, and identifies key cycle time factors. This intermediary transforms the complex, high-dimensional manufacturing process data into manageable insights about critical process steps and bottlenecks.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a virtual copy or digital twin of the manufacturing process through data collection and neural network modeling. Instead of directly analyzing the physical complex process, the system creates a computational model that replicates process behavior, allowing analysis of cycle time factors in the virtual model without disrupting the actual manufacturing process.

Inventive Principle:
Principle #26Copying

3Adaptability or versatility

If more process stages and steps are added to handle complex manufacturing requirements, then the manufacturing versatility improves, but the cycle time increases due to more work-in-process

Engineering Contradiction:
Improvemanufacturing process flexibilityVSAvoidcycle time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent implements a feedback mechanism where the neural network continuously monitors manufacturing process data, identifies bottlenecks and cycle time drivers, and provides insights for process optimization. This feedback loop enables dynamic adjustment of process parameters and resource allocation to minimize cycle time while maintaining the necessary manufacturing versatility for complex products.

Inventive Principle:
Principle #23Feedback

Data Source

PatentUS20240385604A1Method and system for reducing work-in-process
Publication Date: 2024.11.21 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD
  • US20240385604A1 patent drawing
  • US20240385604A1 patent drawing
  • US20240385604A1 patent drawing

AI summary

A method for improving a cycle time of a process of a product is provided. The method includes: collecting process profile data from a plurality of tool groups running the process, and calculating values of a plurality of key-performance-indicators (KPIs) of each tool group including calculating a standard deviation of an output of a stage of a bottleneck tool group of the tool groups; feeding the values of the KPIs and a work-in-progress (WIP) of each tool group into a neural network model in order to output an impact on the WIP for each KPI of each tool group by the neural network model; selecting a set of major KPIs of each tool group from the KPIs according to the impact of each tool group; and controlling the tool groups according to the impact of the set of major KPIs of each tool group in order to reduce a total WIP.