An attribute control chart for the inverse Weibull distribution under truncated life tests

Area of Science:

• Industrial Engineering
• Quality Control
• Reliability Engineering

Background:

• Statistical Process Control (SPC) is crucial for monitoring production processes and identifying issues.
• Monitoring product quality often involves life tests, which can be time-consuming.
• Truncated life tests offer a practical alternative by limiting test duration.

Purpose of the Study:

• To develop a novel control chart for quality monitoring under truncated life test conditions.
• To adapt Statistical Process Control (SPC) methodologies for situations with Inverse Weibull distributed product lifetimes.
• To enhance the detection of process deviations in quality assessment.

Main Methods:

• Utilizing truncated life tests where product lifetimes are observed up to a pre-specified time.
• Applying the Inverse Weibull distribution to model product lifetimes.
• Employing simulation techniques to determine control chart parameters and achieve target Average Run Length (ARL).

Main Results:

• A new control chart was successfully developed for truncated Inverse Weibull life tests.
• Control chart coefficients and truncation coefficients were determined for various sample sizes and ARL targets.
• The proposed chart demonstrated effectiveness in detecting out-of-control process conditions.

Conclusions:

• The proposed control chart extends the application of SPC to truncated life testing scenarios.
• This methodology provides a valuable tool for quality monitoring in industries with long product lifetimes.
• The study offers practical guidance for implementing control charts with truncated life tests.