Production Quality Control Using Correlation-Based Defect Prevention
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Solution Overview
Problem
Conventional quality control methods struggle to identify the cause of defects and provide effective measures for future improvements, despite being able to detect defect occurrence and periods in which they occur.
Innovation Solution
A quality control device that includes an input unit for receiving operation conditions, a calculation unit applying a correlation formula to determine the quality of the production process, and an output unit for determining the quality and identifying causes of defects, allowing for adjustments in operation conditions to prevent future defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional quality control methods are used to monitor production processes, then defect occurrence can be detected, but the cause of defects cannot be identified and effective preventive measures cannot be provided
Solution Approach 1:
The patent transitions from conventional single-dimension quality control (monitoring individual control items separately) to multi-dimensional correlation analysis. By establishing correlation formulas that integrate multiple control items and their interrelationships, the system can identify defect causes by analyzing patterns across multiple dimensions simultaneously, not just detecting that a defect occurred.
Solution Approach 2:
The patent introduces correlation formulas as intermediary tools that mediate between raw control item data and defect cause identification. These formulas serve as the bridge that transforms individual control item measurements into meaningful cause analysis by calculating correlation values that indicate the relationship between control items and quality outcomes.
2Productivity
If conventional quality control focuses on individual control items in each process, then manufacturing can proceed according to control items, but the relationship between quality and control items remains insufficient
Solution Approach 1:
The patent merges individual control item monitoring into a unified correlation analysis system. By combining multiple control items and their relationships into integrated correlation formulas, the system maintains manufacturing continuity while simultaneously analyzing the precise relationships between control items and quality outcomes, resolving the contradiction between productivity and precision.
Solution Approach 2:
The correlation formulas serve multiple functions: they monitor control items, identify defect causes, and provide preventive guidance. This multi-functionality allows the system to maintain manufacturing continuity while simultaneously achieving precise quality-control relationships, as the same formulas support both productivity and precision objectives.
3Measurement precision
If statistical methods are used to set control limits based on past data, then control limits can be established, but guidance on how to take measures in the future cannot be provided
Solution Approach 1:
The patent implements feedback by using correlation analysis results to provide actionable guidance back to the manufacturing process. The system not only establishes control limits but also feeds back information about which control items are most strongly correlated with quality outcomes, enabling operators to take targeted preventive measures based on the identified relationships.
Solution Approach 2:
The patent enables preliminary action by identifying defect causes before actual defects occur. Through correlation analysis of control items and quality outcomes, the system can predict which control item adjustments will prevent future defects, allowing preventive measures to be taken in advance rather than reacting after defects occur.
Data Source
AI summary
In order to realize stable quality control, provided is a quality control device (1) having an input device which receives data such as an operation condition of each device (21) to (26) in a production system (20) for producing a product; a calculation unit which assigns a value of the operation condition to a correlation formula calculated in advance and calculates a value derived from the correlation formula; and a determination unit which performs good or bad determination on a quality of a workpiece in each process, on the basis of a result calculated by the calculation unit. Further, when “bad” is determined as a result of the good or bad determination, the quality control device (1) calculates an appropriate value of the operation condition and sets the value to each device (21) to (26).