Warranty Data Analysis Dates Format Example
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Assume a company has the following information for a product.
Sales
| Quantity In-Service | Date In-Service |
| 6316 | 1/1/2010 |
| 8447 | 2/1/2010 |
| 5892 | 3/1/2010 |
| 596 | 4/1/2010 |
| 996 | 5/1/2010 |
| 8977 | 6/1/2010 |
| 2578 | 7/1/2010 |
| 8318 | 8/1/2010 |
| 2667 | 9/1/2010 |
| 7452 | 10/1/2010 |
| 1533 | 11/1/2010 |
| 9393 | 12/1/2010 |
| 1966 | 1/1/2011 |
| 8960 | 2/1/2011 |
| 6341 | 3/1/2011 |
| 4005 | 4/1/2011 |
| 3784 | 5/1/2011 |
| 5426 | 6/1/2011 |
| 4958 | 7/1/2011 |
| 6981 | 8/1/2011 |
Returns
| Quantity Returned | Date of Return | Date In-Service |
| 2 | 10/29/2010 | 10/1/2010 |
| 1 | 11/13/2010 | 10/1/2010 |
| 2 | 3/15/2011 | 10/1/2010 |
| 5 | 4/10/2011 | 10/1/2010 |
| 1 | 11/13/2010 | 11/1/2010 |
| 2 | 2/19/2011 | 11/1/2010 |
| 1 | 3/11/2011 | 11/1/2010 |
| 2 | 5/18/2011 | 11/1/2010 |
| 1 | 1/9/2011 | 12/1/2010 |
| 2 | 2/13/2011 | 12/1/2010 |
| 1 | 3/2/2011 | 12/1/2010 |
| 1 | 6/7/2011 | 12/1/2010 |
| 1 | 4/28/2011 | 1/1/2011 |
| 2 | 6/15/2011 | 1/1/2011 |
| 3 | 7/15/2011 | 1/1/2011 |
| 1 | 8/10/2011 | 2/1/2011 |
| 1 | 8/12/2011 | 2/1/2011 |
| 1 | 8/14/2011 | 2/1/2011 |
Future Sales
| Quantity In-Service | Date In-Service |
| 5000 | 9/1/2011 |
| 5000 | 10/1/2011 |
| 5000 | 11/1/2011 |
| 5000 | 12/1/2011 |
| 5000 | 1/1/2012 |
Using the above information, we want to estimate the failure distribution of this product and forecast warranty returns.
Solution
Step 1: The data can be entered into a warranty folio with the dates-of-failure format, as shown in the figures below.
Step 2: Set the calculation setting as shown next:
Make sure the End of Observation Period is 8/14/2011.
Step 3: After you click the Calculate Button, you will get the results shown in the Analysis Summary area in the above figure. You can also click anywhere inside the Analysis Summary area to view more results.
In the bottom part of the above figure, you can see the warranty data is converted to a format that can be used in a Weibull++ standard folio.
Step 4: Click on the Forecast button 
to get the following forecast window.
Click OK to get the forecast return for the future months. Please remember, the current time was set to 8/14/2011.
Step 5: Click the Plot icon and choose the Expected Failures plot. The predicted number of returns for each month was plotted.
The remaining plots in the Plot Type drop-down list are the same plots in the Webull++ standard folio.