This example examines the effect of changing some of the arc costs. The backorder penalty costs are increased by 20 percent. The sales profit of 25-inch TVs sent to the shops in May is increased by 30 units. The backorder penalty costs of 25-inch TVs manufactured in May for April consumption is decreased by 30 units. The production cost of 19-inch and 25-inch TVs made in May are decreased by 5 units and 20 units, respectively. How does the optimal solution of the network after these arc cost alterations compare with the optimum of the original network?

These SAS statements produce the new NODEDATA= and ARCDATA= data sets:

title2 'Minimum Cost Flow problem- Altered Arc Data';
data arc2;
   set arc1;
   oldcost=_cost_;
   oldfc=_fcost_;
   oldflow=_flow_;
   if key_id='backorder' 
      then _cost_=_cost_*1.2;
      else if _tail_='f2_may_2' then _cost_=_cost_-30;
   if key_id='production' & mth_made='May' then
      if diagonal=19 then _cost_=_cost_-5;
                     else _cost_=_cost_-20;
   run;

proc intpoint
   bytes=100000
   printlevel2=2
   nodedata=node0
   arcdata=arc2
   conout=arc3;
   run;

proc print data=arc3;
var _tail_ _head_ _capac_ _lo_ _supply_ _demand_ _name_ 
 _cost_ _flow_ _fcost_ oldcost oldflow oldfc 
 diagonal factory key_id mth_made;
 /* to get this variable order */
     sum oldfc _fcost_;
run;

The following notes appear on the SAS log:

The solution is displayed in Output 5.2.1.