Degradation analysis Weibull 6

[LC Ng]

I would like to know what does the std dev value calculated from the degradation analysis represent ?
Take the example in the Weibull ver 6 example per degradation analysis : The Turbine blade example : ( Unit ID A ) . How does the std dev( 0.049585) derived ?

[adamantios]

The std column in the degradation analysis tool in Weibull++ 6, provides the standard error of the linear regression. It is the estimate of the standard deviation of Y at a given value of x, and it is calculated using the following eqn:

Std=sqrt(MSR)

MSR is the Mean Square for the residuals and is obtained from:

MSR=SSR/(n-2)

SSR is the sum of squares of the residuals given by:

SSR=Sum(Y(i)-Ye(i))

A perfect fit (i.e. no deviation from the points) will return a standard error value of zero.