Dear Bug users,
I am wondering if anyone may give me an answer to my question. I have a set
of data indicating the number of failures over a specific time period for
different components, with a few zero number of failures in the data. I used
WinBUG1.4 to calculate failure rates for the components and what I found is
that (1) if the failure number of a component in the data is not zero, the
calculated failure rate is close to the estimated failure rate (failure
number divided by time) of that component; and (2) if the failure number in
the data is zero, the calculated mean failure rate of that component is
large (larger than the mean of calculated failure rate, i.e., the mean of
the population variability) instead of being small. I made a lot of changes
to the prior and parameters but the problem persists.
The data file has been tested using Chi-square test and it turns to be ok.
If anyone can tell me what the problem is or offer an explaination, I will
greatly appreciated. Should further information regarding the model and the
data, please let me know.
Meng
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