Test-Fix-Test Data Reference Example: Difference between revisions

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{{Reference_Example_Heading2}}
{{Reference_Example_Heading2}}
{| {{table}}
{| {{table}}
|Termination Time = 500 hours
!Termination Time = 500 hours
|-
|-
| 0.2
| 0.2
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{{Reference_Example_Heading3}}
{{Reference_Example_Heading3}}
Beta = 0.413, Lambda = 1.769
Beta = 0.413, Lambda = 1.769
DMTBF = 52.7
DMTBF = 52.7
Confidence Bounds on DMTBF (CL = 80%) = (35.6, 82.9)
Confidence Bounds on DMTBF (CL = 80%) = (35.6, 82.9)


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::<math>\begin{align}
::<math>\begin{align}
\hat{\beta }=&\frac{N}{{N\ln T^{*}}-\sum_{i=1}^{N}T_{i}}\\
\hat{\beta }=&\frac{N}{{N\ln T^{*}}-\sum_{i=1}^{N}T_{i}}\\
 
\\
=&\frac{23}{{23\cdot \ln \left ( 500 \right )}-87.2106}\\
=&\frac{23}{{23\cdot \ln \left ( 500 \right )}-87.2106}\\
 
\\
=&0.4127
=&0.4127
\end{align}\,\!</math>
\end{align}\,\!</math>
Line 81: Line 83:
::<math>\begin{align}
::<math>\begin{align}
\hat{\lambda }=&\frac{N}{T^{*\beta }}\\
\hat{\lambda }=&\frac{N}{T^{*\beta }}\\
 
\\
=&\frac{23}{500^{0.4127}}\\
=&\frac{23}{500^{0.4127}}\\
 
\\
=&0.1.7691
=&0.1.7691
\end{align}\,\!</math>
\end{align}\,\!</math>

Revision as of 23:19, 6 June 2014

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Test-Fix-Test Data Reference Example

This example compares the results for test-fix-test data (time terminated).


Reference Case

Crow, L.H., Confidence Interval Procedures for the Weibull Process with Applications to Reliability Growth, U.S. Army Material Systems Analysis Activity, 1981.


Data

Termination Time = 500 hours
0.2
4.2
4.5
5
5.4
6.1
7.9
14.8
19.2
48.6
85.8
108.9
127.2
129.8
150.1
159.7
227.4
244.7
262.7
315.3
329.6
404.3
486.2


Result Beta = 0.413, Lambda = 1.769

DMTBF = 52.7

Confidence Bounds on DMTBF (CL = 80%) = (35.6, 82.9)


Results in Weibull++

[math]\displaystyle{ \begin{align} \hat{\beta }=&\frac{N}{{N\ln T^{*}}-\sum_{i=1}^{N}T_{i}}\\ \\ =&\frac{23}{{23\cdot \ln \left ( 500 \right )}-87.2106}\\ \\ =&0.4127 \end{align}\,\! }[/math]


[math]\displaystyle{ \begin{align} \hat{\lambda }=&\frac{N}{T^{*\beta }}\\ \\ =&\frac{23}{500^{0.4127}}\\ \\ =&0.1.7691 \end{align}\,\! }[/math]


CB for Weibull Results.png


CB for Weibull QPC.png