procmean.gms : Optimal Process Mean
Find the optimal process mean when the quality characteristic
follows a Beta distribution and using a linear quality loss.
References:
- Chen, C H, and Chou, C Y, Determining the Optimum Process Mean under a Beta Distribution. Journal of the Chinese Institute of Industrial Engineers 18 (3) (2003), 27--32.
- Phillips, M D, and Cho, B R, Determining the Optimum Process Mean under a Beta Distribution. A Nonlinear model for determining the most economic process mean under a beta distribution 7 (2000), 61--74.
Small Model of Type: NLP
$Title Optimal Process Mean (PROCMEAN,SEQ=301)
$ontext
Find the optimal process mean when the quality characteristic
follows a Beta distribution and using a linear quality loss.
Erwin Kalvelagen, April 2004
Chen, C H, and Chou, C Y, Determining the Optimum Process Mean under a
Beta Distribution. Journal of the Chinese Institute of Industrial
Engineers 18 (3) (2003), 27--32.
Phillips, M D, and Cho, B R, Determining the Optimum Process Mean
under a Beta Distribution. A Nonlinear model for determining the most
economic process mean under a beta distribution 7 (2000), 61--74.
$offtext
scalars
a 'minimum value of quality characteristic' /113/
b 'maximum value of quality characteristic' /119/
alpha 'shape parameter' /2/
beta 'shape parameter' /4/
T 'target value' /115/
k1 'quality loss coefficient when xT' /3/
;
scalars g1,g2,g3;
g1 = gamma(alpha+beta)/(gamma(alpha)*gamma(beta));
g2 = gamma(alpha+1)*gamma(beta)/gamma(alpha+beta+1);
g3 = g1*g2;
variables
TC 'Total expected cost per unit'
delta 'location parameter'
y 'transformation'
;
equations
tcdef 'cost model'
ydef
;
tcdef.. tc =e= k1*T*betareg(y,alpha,beta)
- k1*{(delta+a)*betareg(y,alpha,beta)
+(b-a)*betareg(y,alpha+1,beta)*g3}
+ k2*{(delta+a)*[1-betareg(y,alpha,beta)]
+(b-a)*[1-betareg(y,alpha+1,beta)*g3]}
- k2*T*[1-betareg(y,alpha,beta)];
ydef.. y =e= (T-delta-a)/(b-a);
y.lo = 0.0001;
y.up = 0.9999;
y.l = 0.5;
model m /all/;
solve m using nlp minimizing tc;