Hi;

I am trying to code equations 26, 27, 28, 29, 30 and 31 in the attachment file.

y(Y) is index(Set) of years,

sets

y years /1*10/

i production units

Iaday(i) new production units that will be added to the system

Imevcut(i) existing production units in the system

tho /1*50/ (I defined to 1 to 50 which is large enough)

parameters

Tlife(i) economic life of production units it is between 25 and 50

Tini(i) age of unit i in the beginning of the planning horizon (years). If negative, its absolute value represents the year of planned commissioning of the unit (with firm decision at a prior stage)

Tcons(i) construction time of unit i (years)

binary variables

u(i,y) the status of new unit i in year y equal to 1 if unit is commissioned

w(i,y) binary variable representing the start-up decision (commissioning) of the new unit i in year y

z(i,y) binary variable representing the shut-down decision (decommissioning) of the new unit i in year y

equ26(Iaday,y)… sum(tho$(ord(tho) ge ord(y)-Tlife(Iaday)+1 and ord(tho) le ord(y)),w(tho,Iaday))=e=u(Iaday,y);

equ27(Iaday,y)… sum(tho$(ord(tho) ge ord(y)-capsY+1 and ord(tho) le ord(y)),z(tho,Iaday))=l=1- u(Iaday,y);

loop(Imevcut,

loop(y,

if ( ((-Tini(Imevcut) =ord(y))),

u(Imevcut,y)=1;

else

u(Imevcut,y)=0;

);

);

);

loop(Imevcut,

loop(y,

if ( ((Tlife(Imevcut)-Tini(Imevcut))=ord(y)),

u(Imevcut,y)=1;

else

u(Imevcut,y)=0;

);

);

);

loop(Iaday,

loop(y,

if ( ord(y)=ord(y))),

5353 u(Imevcut,y)=1;

**** $143

5354 else

5355 u(Imevcut,y)=0;

**** $143

5356 );

5357 );

5358 );

5359 loop(Imevcut,

5360 loop(y,

5361 if ( ((Tlife(Imevcut)-Tini(Imevcut))=ord(y)),

5362 u(Imevcut,y)=1;

**** $143

5363 else

5364 u(Imevcut,y)=0;

**** $143

5365 );

5366 );

5367 );

5368 loop(Iaday,

5369 loop(y,

5370 if ( ord(y)<Tcons(Iaday),

5371 u(Iaday,y)=0;

**** 143
5372 );
5373 );
5374 );
5375
5376 equ26(Iaday,y).. sum(tho(ord(tho) ge ord(y)-Tlife

(Iaday)+1 and ord(tho) le ord(y)),w(tho,Iaday))=e=u(Iaday,y);

**** $171 171
5377 equ27(Iaday,y).. sum(tho(ord(tho) ge ord(y)-capsY

**** $

+1 and ord(tho) le ord(y)),z(tho,Iaday))=l=1- u(Iaday,y);

140 $171 $171

What’s the problem? How can I solve this problem. Please, help me.

Thanks to everbody

–