Design of ALT Control Chart for Small Process Variation

미세변동공정관리를 위한 가속수명시험관리도 설계

  • Received : 2012.07.20
  • Accepted : 2012.09.12
  • Published : 2012.09.30


In the manufacturing process the most widely used $\bar{X}$ chart has been applied to control the process mean. Also, Accelerated Life Test(ALT) is commonly used for efficient assurance of product life in development phases, which can be applied in production reliability acceptance test. When life data has lognormal distribution, through censored ALT design so that censored ALT data has asymptotic normal distribution, $ALT\bar{X}$ control chart integrating $\bar{X}$ chart and ALT procedure could be applied to control the mean of process in the manufacturing process. In the situation that process variation is controlled, $Z_p$ control chart is an effective method for the very small fraction nonconforming of quality characteristic. A simultaneous control scheme with $ALT\bar{X}$ control chart and $Z_p$ control chart is designed for the very small fraction nonconforming of product lifetime.


  1. Bai, Chun and Kim, "Failure-Censored Accelerated Life Test Sampling Plans for Weibull Distribution under Expected Test Time Constrain," Reliability Engineering and System Safety, Vol.50, pp61-68, 1995
  2. Bai, Kim and Chun, "Design of Failure-Censored Accelerated Life-Test Sampling Plans for Lognormal and Weibull Distribution," Engineering Optimization, Vol.21, pp197-212, 1993
  3. F. F. Gan, "Design of Optimal Exponential CUSUM Control Chart," Journal of Quality Technology, Vol.26(2), pp109-124, 1994
  4. Harry, "Confidence Intervals for the Percent Nonconforming Based on Variables Data," Journal of Quality Technology, Vol.14(4), pp207-210, 1982
  5. D. S. Holmes and A. E. Mergen, "EWMA Acceptance Chart," Quality and Reliability Engineering International, Vol.16(2), pp1-4, 2000<1::AID-QRE324>3.0.CO;2-9
  6. B. C. Khoo, "A Moving Average Control Chart for Monitoring the Fraction Non-conforming," Quality and Reliability Engineering International, Vol.20, pp617-635, 2004
  7. J. G. Kim, Design of Accelerated Life Test Sampling Plans for Lognormal and Weibull Distributions, Korea Advanced Institute of Science and Technology, 1993
  8. J. G. Kim, "Design of a Process Reliability Assurance System based on Accelerated Tests," The Journal of Reliability Engineering Association of Japan, Vol.23(7), pp257-260, 2001
  9. J. M. Lucas, "Combined Shewhart-CUSUM Quality Control Schemes," Journal of Quality Technology, Vol.14(2), pp51-59, 1982
  10. J. M. Lucas, "Counted Data CUSUM's," Technometrics, Vol.27(3), pp129-144, 1985
  11. J. I. McCool and T. A. Joyner-Motley, "Control Charts Applicable When the Fraction Nonconforming is Small," Journal of Quality Technology, Vol.30(3), pp240-247, 1998
  12. D. C. Montgomery, Introduction to Statistical Quality Control, John Wiley & Sons, NewYork, 2008
  13. L. S. Nelson, "A Control Chart for Parts-per-Million Nonconforming Items," Journal of Quality Technology, Vol.26(3), pp239-240, 1994
  14. Nelson and B. Wayne, Applied life data analysis, John Wiley & Sons, 2003
  15. Z. Wu, S. H. Yeo and T. A. Spedding, "A Synthetic Control Chart for Detecting Fraction Nonconforming Increases," Journal of Quality Technology, Vol.33, pp104-111, 2001