This function calculates the required test time or sample size for a Reliability Demonstration Test (RDT) based on specified reliability, mission time, confidence level, and Weibull shape parameter.
Arguments
- target
Required reliability at mission time (0 < target < 1).
- mission_time
Mission duration (time units). Must be greater than 0.
- conf_level
Desired confidence level (e.g., 0.9 for 90% confidence). The confidence level must be between 0 and 1 (exclusive).
- beta
Weibull shape parameter (beta=1 corresponds to exponential distribution). Must be greater than 0. Default is 1.
- n
Sample size (optional, supply if solving for test_time). Must be a positive integer.
- test_time
Test time per unit (optional, supply if solving for n). Must be greater than 0.
Value
The function returns an object of class rdt that contains:
- Distribution
Type of distribution used (Exponential or Weibull).
- Beta
Weibull shape parameter.
- Target_Reliability
Specified target reliability.
- Mission_Time
Specified mission time.
- Required_Test_Time
Calculated required test time (if n is provided).
- Input_Sample_Size
Provided sample size (if test_time is calculated).
- Required_Sample_Size
Calculated required sample size (if test_time is provided).
- Input_Test_Time
Provided test time (if n is calculated).
Examples
#' # Example 1: Calculate required test time
plan1 <- rdt(target = 0.9, mission_time = 1000, conf_level = 0.9, beta = 1, n = 10)
print(plan1)
#> Reliability Demonstration Test (RDT) Plan
#> -----------------------------------------
#> Distribution: Exponential
#> Weibull Shape Parameter (Beta): 1
#> Target Reliability: 0.9
#> Mission Time: 1000
#> Input Sample Size (n): 10
#> Required Test Time (T): 2185.43
# Example 2: Calculate required sample size
plan2 <- rdt(target = 0.9, mission_time = 1000, conf_level = 0.9, beta = 1, test_time = 2000)
print(plan2)
#> Reliability Demonstration Test (RDT) Plan
#> -----------------------------------------
#> Distribution: Exponential
#> Weibull Shape Parameter (Beta): 1
#> Target Reliability: 0.9
#> Mission Time: 1000
#> Input Test Time (T): 2000
#> Required Sample Size (n): 11