TY - GEN
T1 - Application of generalized linear models for optimizing production stress testing
AU - Honari, Bahman
AU - Donovan, John
AU - Joyce, Toby
AU - Wilson, Simon
PY - 2008
Y1 - 2008
N2 - Accelerated environmental stress tests (EST) are applied during the manufacturing process to improve reliability by precipitating and detecting latent defects. This test represents an in-process manufacturing screen and the objective of performing it is to avoid early field failures that reduce the customer satisfaction level and increase warranty and compensation costs. Temperature cycling during EST is one of the most commonly used test procedures. Although it is an expensive and energy intensive procedure, usually a lengthy test is initially recommended for a new product. Based on the product test performance or a possible manufacturing process modification, the test duration and regime may be changed after some period. Even if the number of test cycles is reduced, EST continues to be an expensive test and a major process bottleneck. This paper uses Generalized Linear Modeling (GLM) to investigate the effects of the production and EST test variables on the population under test. Both the number of units rejected and the time to failure can be modeled as a regression function of covariates representative of the test environment. The field reliability function is written as a product of the unconditional reliability in each segment of the test profile such as dwell, ramp, etc. The next step is to apply the result of the temperature cycle EST GLM to a mathematical cost model. This cost model includes both the test cost and the warranty and compensation costs of the early field failures. The optimum test regime and number of cycles, which minimizes the total cost is determined by combining the GLM and the cost model. In this way the production test regime can be optimized in terms of field reliability/test cost trade-off.
AB - Accelerated environmental stress tests (EST) are applied during the manufacturing process to improve reliability by precipitating and detecting latent defects. This test represents an in-process manufacturing screen and the objective of performing it is to avoid early field failures that reduce the customer satisfaction level and increase warranty and compensation costs. Temperature cycling during EST is one of the most commonly used test procedures. Although it is an expensive and energy intensive procedure, usually a lengthy test is initially recommended for a new product. Based on the product test performance or a possible manufacturing process modification, the test duration and regime may be changed after some period. Even if the number of test cycles is reduced, EST continues to be an expensive test and a major process bottleneck. This paper uses Generalized Linear Modeling (GLM) to investigate the effects of the production and EST test variables on the population under test. Both the number of units rejected and the time to failure can be modeled as a regression function of covariates representative of the test environment. The field reliability function is written as a product of the unconditional reliability in each segment of the test profile such as dwell, ramp, etc. The next step is to apply the result of the temperature cycle EST GLM to a mathematical cost model. This cost model includes both the test cost and the warranty and compensation costs of the early field failures. The optimum test regime and number of cycles, which minimizes the total cost is determined by combining the GLM and the cost model. In this way the production test regime can be optimized in terms of field reliability/test cost trade-off.
KW - Environmental stress testing
KW - Generalized linear models
KW - Test optimization
UR - http://www.scopus.com/inward/record.url?scp=67650031892&partnerID=8YFLogxK
U2 - 10.1109/RAMS.2008.4925806
DO - 10.1109/RAMS.2008.4925806
M3 - Conference contribution
AN - SCOPUS:67650031892
SN - 142441461X
SN - 9781424414611
T3 - Proceedings - Annual Reliability and Maintainability Symposium
SP - 267
EP - 271
BT - 2008 Proceedings - Annual Reliability and Maintainability Symposium, RAMS 2008
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 54th Annual Reliability and Maintainability Symposium, RAMS 2008
Y2 - 28 January 2008 through 31 January 2008
ER -