Website Upgrade Incoming - we're working on a new look (and speed!) standby while we finalise the project

Tips on using this forum..

(1) Explain your problem, don't simply post "This isn't working". What were you doing when you faced the problem? What have you tried to resolve - did you look for a solution using "Search" ? Has it happened just once or several times?

(2) It's also good to get feedback when a solution is found, return to the original post to explain how it was resolved so that more people can also use the results.

Using Crystal Ball for Simple Analysis

4 replies [Last post]
Martin Selley
User offline. Last seen 2 years 39 weeks ago. Offline
Joined: 4 Mar 2006
Posts: 7

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.

Replies

Rafael Davila
User offline. Last seen 1 week 6 days ago. Offline
Joined: 1 Mar 2004
Posts: 5241

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).

Martin Selley
User offline. Last seen 2 years 39 weeks ago. Offline
Joined: 4 Mar 2006
Posts: 7

 

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

Rafael Davila
User offline. Last seen 1 week 6 days ago. Offline
Joined: 1 Mar 2004
Posts: 5241

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/200...

make a search on the PDF for Cumulative

Photobucket

Best regards,

Rafael

Mike Testro
User offline. Last seen 36 weeks 16 hours ago. Offline
Joined: 14 Dec 2005
Posts: 4418

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