Instructions |

User has to enter the total Number of items involved in the analysis and the Number N of triads in the input file.
It is convenient to store the data in a file when one has a large number of points.
It should be a text file (with .txt extension), which contains exactly N triads in any order.
Each triad consists of value corresponding to event time (double or float) followed by an integer 0 or 1.
Integer 1 corresponds to the event (for example, item failure). Integer 0 corresponds to suspension (right censoring), if happened during the item observation.
Last value in the triad should also be an integer and it indicates the number of items involved in the current event.
The sum of all items in the input file should correspond to the above total Number of items.
If it is less than this Number, the remaining items are assumed suspended at the Observation time.
If it is convenient, the user can prepare input data in Excel format and then copy and paste the data in a .txt file and use it in the calculation.
Each number in the file should be separated by white space or new line ("Enter"). Note that two integer numbers without separator will be read as one number, for example "23" and "67" will be read as "2367". Two float numbers without separator could be corrupted, for example "0.34" and "3.5" typed as "0.343.5" can be read as "0.343" and "0.5". We check the format of input numbers and in the most cases one will get an error message if the format is not valid, but it is the responsibility of the user to prepare the input data properly. We also check for consistency of the input set of numbers. One can use "Browse" to select the required file and click "Upload" to submit. On the next page user should select underlying probability distribution function: Exponential, Weibull, Normal or Log-Normal. Then the ranking method of converting input times to probability values should be selected: Benard, Hazen or Mean. The ranking method is used if the Regression method (Regression on X or Regression on Y) is selected and to represent the probability values on the diagram. Maximum Likelihood method is also available and it is recommended in most cases, especially if suspension factor is significant and the number of components is small. Then user should input the Confidence level (for example 0.9), the type of confidence bounds and the method of calculation of confidence bounds: Fisher matrix or Likelihood ratio. The last one is more time consuming, but even in this case all analysis takes only several seconds. User has to enter the upper bound for probability interval. The calculation result will be displayed at this interval. After clicking “Calculate” you will get result on the same page. You can change calculation options on this page without uploading the same input file, if the session has not timed out. |