ASQ RRD series webinar: How to Graph, Analyze, and Compare Sets of Repair Data
Presenter: Dr. Wayne B. Nelson
Thursday, February 13, 2025 12:00 PM – 1:00 PM
(UTC-04:00) Eastern Time (US & Canada)
https://asq.webex.com/weblink/register/r376b7d4ec0dc388988abf96d0af86142
Abstract. Many products accumulate repeated repairs and repair costs over time. Analysis of such recurrence data requires special statistical models and methods not covered in basic reliability books. This webinar presents a general simple and informative model and plot for analyzing data on numbers or costs of repeated repairs of a sample of units. The plot provides:
The plots and analyses are illustrated with data on car transmission repairs, bladder tumor recurrences, childbirths to statisticians, amazon.com sales, and other applications. Computer programs that calculate and make the plots and comparisons with confidence limits are surveyed.
1. An estimate of the average number or cost of repairs per unit during warranty or design life.
2. The behavior of the population repair rate – does it increase or decrease with population age? This information is used to make decisions on product burn-in, overhaul, preventive replacement, and retirement.
3. Predictions of the future number or cost of repairs for a unit or the population. This is used to predict warranty costs and the demand for replacement parts.
4. A comparison of data sets from different populations. This is used to decide which designs, materials, treatments, environments, etc., produce lower repair rates.
5. Unsought useful information.
Dr. Wayne B. Nelson consulted across General Electric for 24 years. He now consults on reliability data analysis and provides reliability training for major corporations and professional societies. He was elected a Fellow of the American Society for Quality, the IEEE, and the American Statistical Assoc. for his outstanding contributions to reliability data analysis. He was awarded the Shewhart Medal and Shainin Medal of ASQ and the 2005 Lifetime Achievement Award of the IEEE Reliability Society for his outstanding technical developments and reliability education. He authored three books Applied Life Data Analysis (Wiley 1982,2004), Accelerated Testing (Wiley 1990,2004), Recurrent Events Data Analysis (SIAM 2003), two ASQ booklets, and 140 journal articles.