Tip: For a quick demonstration, select a test data set from the last pull-down in the Options area (#4) and click calculate.
The data input format (time-to-failure, box 1 below) is a failure time followed by either an "f" or an "s", indicating a failure or suspension (i.e., item did not fail), one record per line. Box #1 is prefilled with example input data for six test items. The first item was taken off test (suspended) at 42.1 hours and the final item failed at 139.1 hours.
The following provides an example for grouped, or interval data input. The columns are "time-to-failure", "f" or "s" indicating a failure or suspension, "g" indicating grouped data, followed by the number of items in the group. The following shows example input for 93 items placed on test. Between test start and 10 hours, one item failed. Between 10 and 20 hours 11 failures occurred. After 50 hours 8 items still did not fail and the test was stopped, indicated by an "s" in the second column of the final input line. The analysis results from this input assume that failures occur at the end of the interval. If failures can occur anytime during the interval, then a more accurate approach is to enter mid-point times for the interval (i.e., change the first four times to 5, 15, 25 and 35).
10 f g 1
20 f g 11
30 f g 28
40 f g 45
50 s g 8