ACME Example

ACME Example
ACME manufacturing has implemented an accelerated testing program for their new design. A total of 40 units were tested at four different pressure levels. The operating stress level is 170 psi.

Do the following:

1) Determine the parameters of the inverse power law Weibull model.

2) Obtain the use level probability plot with 90% 2-sided confidence bounds on time.

3) Obtain the Life vs. Stress plot with 90% 2-sided confidence bounds.

Solution
1) The parameters of the IPL-Weibull model are estimated to be:


 * $$\begin{align}

\beta =\ & 3.009236 \\

K=\ & 3.267923E-27 \\

n=\ & 10.218104

\end{align}$$

2) The use level probability plot is shown next.



The confidence bounds on time are the Type 1 bounds (Time Bounds) in ALTA.



3) Similarly, the Life vs. Stress plot with the confidence bounds can be obtained.