Motores Diesel

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| |by William W. Dorner | |

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|Download the Excel worksheet used in this article |
|Netscape users may need to download this Zipped version instead. Weibull.zip |
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|Many people useMicrosoft Excel on a daily basis. Yet few people realize the extent of Excel's analytical capabilities. Fewer still put these |
|capabilities to work for process improvement, product improvement and profit.Most Excel users are aware of the common formulas and charts. But|
|with some creativity, users can produce tools like control charts, Pareto charts and box-and-whisker plots (see "Using Excelfor Data |
|Analysis," Quality Digest, October 1997). And with a little guidance, users can employ more advanced statistical methods with Excel. This |
|article presents a how-to approach for one such advanced technique-Weibull analysis. |
|You haven't turned the page yet? Those of you who remain probably fall under one oftwo categories: those familiar with reliability data |
|analysis, and Excel enthusiasts who are curious to learn one more way to exploit this versatile software. I predict readers in both groups |
|will be glad they stuck around. |
|For the uninitiated, Weibull analysis is amethod for modeling data sets containing values greater than zero, such as failure data. Weibull |
|analysis can make predictions about a product's life, compare the reliability of competing product designs, statistically establish warranty |
|policies or proactively manage spare parts inventories, to name just a few common industrial applications. In academia, Weibull analysis has |
|modeledsuch diverse phenomena as the length of labor strikes, AIDS mortality and earthquake probabilities. |
|Learning by example |
|Let's ignore the formulas for now and start by looking at an example of Weibull analysis in action. Imagine that you...