Additional Considerations on a Sequential Life Testing Approach using a Weibull Model

In this paper we will develop further the sequential life test approach presented in a previous article by [1] using an underlying two parameter Weibull sampling distribution. The minimum life will be considered equal to zero. We will again provide rules for making one of the three possible decisions as each observation becomes available; that is: accept the null hypothesis H0; reject the null hypothesis H0; or obtain additional information by making another observation. The product being analyzed is a new type of a low alloy-high strength steel product. To estimate the shape and the scale parameters of the underlying Weibull model we will use a maximum likelihood approach for censored failure data. A new example will further develop the proposed sequential life testing approach.

Authors:

• D. I. De Souza
• D. R. Fonseca
• R. Rocha

Keywords:

• Sequential Life Testing
• Underlying Weibull Model
• Maximum Likelihood Approach
• Hypothesis Testing.

References:

[1] D. I. De Souza, D. R. Fonseca and D. Kipper, "Appling Eyring-s
Accelerated Life Test Model to Times to Breakdown of Insulating Fluid:
A Combined Approach of an Accelerated and a Sequential Life
Testing,", World Academy of Science, Engineering and Tecknology:
Year 6, Issue 7, pp. 77-82, September 2010.
[2] K. Kapur andL. R. Lamberson,Reliability in Engineering Design. New
York:John Willey & Sons, Inc., 1977.
[3] Daniel I. De Souza,"Sequential Life Testing with a Truncation
Mechanism for an Underlying Weibull Model,"Towards a Safer World,
ESREL 2001 Conference, Torino, Italy, vol. 3, pp. 1539 -1546, 16-20
September, 2001.
[4] Daniel I. De Souza, "Sequential Life-Testing with Truncation
Mechanisms for Underlying Three-Parameter Weibull and Inverse
Weibull Models," COMADEM 2004 Conference,Cambridge, U.K.,pp.
260-271, August 2004.