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Schedule Risk and Schedule Risk Analysis

Using Crystal Ball for Simple Analysis

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Martin SelleyMember for 20 years 7 months
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Looking for 'Idiots Guide' type assistance with Crystal Ball (Oracle) as Excel Supplement.

Have never used the Software, downloaded yesterday, and I have to come up with some P10, & 90 Durations for a Manufacturing/testing/shipping schedule due to be received next week.

Would use the Manufacturers Schedule Durations as P50 Input.

Can some one please advise how then to get the P10 & P90 dates.

Thanks.

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  1. 0
    Mike Testro ·
    #1

    Hi Martin Sorry Ican't help

    Hi Martin

    Sorry Ican't help but you seem to be the person to tell Rafael and I what does P10 P50 and P90 mean?

    Best regards

    Mike Testro

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  2. 0
    Rafael Davila ·
    #2

    P10, P50, and P90 I believe

    P10, P50, and P90 I believe refers to points in the Cumulative Probability Curve.

    For specifics on the software look for the manual,

    http://www.biztech.stevens-tech.edu/jkeating/BT%20223/Crystal%20Ball/20091103JJK1%20cb_UserManual.pdf

    make a search on the PDF for Cumulative

    Photobucket

    Best regards,

    Rafael

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  3. 0
    Martin Selley ·
    #3

    P10, P50, P90 percentages

     

    P10, P50, P90 percentages probability of occurance

    P10 is a 10 percent chance of occurance, P50 is a 50 percent chance and P90 is a 90 percent chance of occurance. Used in forecasting of business results

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  4. 0
    Rafael Davila ·
    #4

    Be aware that Probability of

    Be aware that Probability of Occurrence (probability distribution) is not the same as Cumulative Probability (probability of success).

    If an event has a 90% probability of occurrence then the sum of all remaining events probabilities of occurrence is limited to 10% as the summ of all probabilities of occurrence by definition equals 1.00 or 100%.

    Photobucket

    http://www.mcgrawhill.ca/college/olcsupport/siklos4/tables/table%2013.6.pdf

    In the above example the probability of occurrence corresponding to 20% corresponds equally to 3 ranges while the cumulative probability (usually known as probability of success) corresponds to a single range in between the first two.

    Common sense tells me P10, P50 and P90 refers to Cumulative Probability (probability of success) and not to Probability of Occurrence (probability distribution).

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