Available at: http://digitalcommons.calpoly.edu/theses/1749
Date of Award
MS in Industrial Engineering
Industrial and Manufacturing Engineering
Cisco was interested in how field failure categories relate to manufacturing test failures to better predict the tests that should be performed on a product after a return by a customer and what tests will be failed by a product before and after a return by a customer based on what type of failure occurred in the field. A study was conducted on one product type and 5 years of field data and the associated test data were captured. For each combination of field failure, shipping status, test area result, and test area a statistical model of the population proportion was created. The 95% and 99% confidence intervals were found. The critical test areas and a ranking of the criticality of the test areas were arranged from the confidence intervals. These findings will reduce the time spent on unnecessary tests.