qualityTools (version 1.31.1)

desirability: Desirability Function

Description

Creates desirability functions for use in the optimization of multiple responses

Usage

desirability(response, low, high, target = "max", scale = c(1, 1), importance = 1, constraints)

Arguments

response

name of the response

low

lowest acceptable value for the response

high

highest acceptable value for the response

target

desired target value of the response

scale

scaling factors for one and two sided transformations

importance

not yet implemented

constraints

not yet implemented

Value

• a desirability function

Details

For a product to be developed different values of responses are desired leading to multiple response optimization. Minimization, Maximization as well as a specific target value are defined using desirability functions. A desirability function tranforms the values of a response into [0,1] where 0 stands for a non acceptable value of the response and 1 for values where higher/lower (depending on the direction of the optimization) values of the response have little merit.

References

DERRINGER, George; SUICH, Ronald: Simultaneous Optimization of Several Response Variables. Journal of Quality Technology Vol. 12, No. 4, p. 214-219

See Also

desires, optimum,

Examples

#Maximization of a response
#define a desirability for response y where higher values of y are better as long as the response is smaller than high
d = desirability(y, low = 6, high = 18, target = "max")

#show and plot the desirability function
d; plot(d)


#Minimization of a response including a scaling factor
#define a desirability for response y where lower values of y are better as long as the response is higher than low
d = desirability(y, low = 6, high = 18, scale = c(2),target = "min")

#show and plot the desirability function
d; plot(d)

#Specific target of a response is best including a scaling factor
#define a desirability for response y where desired value is at 8 and values lower than 6 as well as values higher than 18 are not acceptable
d = desirability(y, low = 6, high = 18, scale = c(0.5,2),target = 12)

#show and plot the desirability function
d; plot(d)