*>Hi all, does anybody knows how to attack a problem like the following ?>>Z: min (sum t(sum k(Ct,k Xt,k)))>s.t.>1) (sum t(sum k(Ct,k Xt,k)) GE costant>2) (sum k(Qi,k Xt,k)) + Si,t LE Bi,t + Si,t-1 (i:1..I;t:1..T)>3) (sum t(Xt,k)) LE 1 (t:1..T)>4) Xt,k = (0;1)>>All ideas will be appreciated !!!!*

A problem like this is very easily coded in a modeling system like AMPL or GAMS. If I understand the notation correctly this would look like:

binary variable x(t,k);

equations

obj

e1(i,t)

e2(k)

;

obj.. z =e=sum((t,k),C(t,k)*X(t,k));

z.lo = constant;

e1(i,t).. sum(k, Q(i,k)*X(t,k))+S(i,t) =L= B(i,t)+S(i,t-1);

e2(k).. sum(t, X(t,k)) =L= 1;