Crawford vs. Wright Delta Plot

Plots the delta of hours (or cost) per unit between Crawford's unit model and Wright's cumulative average model.

plot_delta(t, m, n, r, level = "u")

Arguments

t

time (or cost) required to produce the mth unit

m

mth unit for which you have time (or cost) information (default is m = 1)

n

the nth unit you wish to predict the time (or cost) for when comparing unit predictions or the last unit in the block when comparing cumulative time (or costs)

r

learning curve rate

level

plot the delta between the Crawford and Wright models at the unit ("u") or cumulative ("c") level

Examples

# The first unit of production is expected to require 50 hours and
# the learning rate is expected to be 88.5%. However, the estimator
# is not sure whether the learning rate is based on the unit model
# or cumulative average model and wants to understand the difference
# between potential outcomes for each unit.  

# Plot the differences between per unit time requirements
plot_delta(t = 50, m = 1, n = 25, r = .885)

# Plot the differences between cumulative time requirements
plot_delta(t = 50, m = 1, n = 25, r = .885, level = "c")