Track 1 Session 9
8:00 to 9:00 a.m. Friday June 22, 2007

The Right Distribution Makes All the Difference!

Typically, four life distributions are used in the analysis of reliability data: Normal, Lognormal, Exponential and Weibull. But, how does one determine which distribution to use? To understand the best distribution for the analysis, an understanding of the failure modes is critical.

This presentation will review the properties and characteristics of each of the four distributions. It will show the analysis of a data set using each of the four distributions and compare the results. It will use the Weibull++ software to do the data analysis. The session will end with a discussion of the importance of understanding the data and the failure modes and the use of critical thinking to assure that the distribution selected by the software is appropriate for the data.

By attending this session, reliability professionals will have a basic understanding of the properties and characteristics of the four commonly used life distributions. They will see the impact of the life distribution on the data analysis and the need to critically question the software distribution choice. They will see an example that illustrates the actual cost of choosing the wrong distribution. Reliability professionals will be able to better determine which distribution to use and the advantages of using the correct distribution.