Taguchi Loss Function pp.
110-111, 604-607
1
Quality is variation from
desired mean expressed as
an economic loss function
2
Function is Loss at measure x =
constant times distance from
desired measure to x squared.
Lx = k((x-T)^2)
• k is the part of a Parabola equation that
controls how flat or vertical the wings are
3
Find k with a known cost at
some measure, usually cost
when out of specification
(scrap, warranty)
4
Can determine average cost per
unit with a process with a given
mean and standard deviation
• expected loss for process with mean x = k
times (variance+square of distance from
mean to target)
5
Can utilize this for one sided
situations (better if bigger or
smaller)
• smaller is better than target L at x = k
times x^2
• bigger is better than target L at x = k time
1/x^2
6
Set parameters to make sure
to minimize cost to company
and customers
7
Truncated curves, see
accompanying excel sheet
8