Lindo Systems

MODEL:
 ! Machine repair model;
 SETS:
  NREP/1..5/: ! Consider 5 possible repair persons;
       NDOWN, ! Expected no. of down machines;
       CPERHR,! Expected cost/hour of down machines;
       TCOST; ! Total expected cost/hour;
 ENDSETS

 ! The input data;
  NMACH = 10;! No. machines subject to breakdown;
  RTIME = 1; ! Average repair time;
  UPTIME = 5;! Mean time between failures;
  CR = 30;   ! Hourly cost of a repair person;
  CM = 350;  ! Hourly cost of a down machine;

 ! The machine repairman queuing model;
 ! For each case of 1 - 5 service people calculate
   expected number of machines down, cost per hour
   of down machines, and total cost per hour of 
   operations. @PFS calculates the Probability in
   a Finite Source, in this case expected number of
   machines under repair. ;
  @FOR( NREP( I):
   NDOWN( I) = 
    @PFS( NMACH * RTIME / UPTIME, I, NMACH);
   CPERHR( I) = CM * NDOWN( I);
   TCOST( I) = CPERHR( I) + CR * I
  );

END