Forecast MTBF from a Duane Model

Takes a fitted duane object and a vector of cumulative times, returning predicted MTBF with confidence bounds as a duane_predict S3 object.

Usage

predict_duane(object, times, conf_level = 0.95)

Arguments

object

An object of class duane returned by duane().

times

A numeric vector of cumulative times at which to forecast MTBF. All values must be finite and > 0. A warning is issued if any value is at or below the maximum observed cumulative time (hindcasting).

conf_level

The desired confidence level (default 0.95). Must be a single finite numeric in (0, 1).

Value

An object of class duane_predict containing:

times

The forecast cumulative times.

mtbf

Predicted MTBF values.

lower_bounds

Lower confidence bounds on MTBF.

upper_bounds

Upper confidence bounds on MTBF.

conf_level

The confidence level used.

duane_object

The original duane object (used by the plot method).

See also

Other Duane functions: duane(), plot.duane(), plot.duane_predict(), print.duane(), print.duane_predict()

Examples

times <- c(100, 200, 300, 400, 500)
failures <- c(1, 2, 1, 3, 2)
fit <- duane(times, failures)
fc <- predict_duane(fit, times = c(1000, 2000))
#> Warning: Some 'times' values are <= the maximum observed cumulative time. Hindcasting is allowed but may not be meaningful.
print(fc)
#> Duane MTBF Forecast 
#> -------------------- 
#>  Time   MTBF Lower (95%) Upper (95%)
#>  1000 149.19      120.39      184.87
#>  2000 171.53      126.35      232.86