Data errors

Even small tables can contain errors. An example data set in a published paper about scheduling maintenance of power generators looks like:

In GAMS I transcribed this as:

table data(i,*)            capacity   allowed-from  allowed-to  outage-weeks *             MW        week           week    number of weeks   unit1      555          1             26           7   unit2      555         27             52           5   unit3      180          1             26           2   unit4      180          1             26           1   unit5      640         27             52           5   unit6      640          1             26           3   unit7      640          1             26           3   unit8      555         27             52           6   unit9      276          1             26          10   unit10     140          1             26           4   unit11      90          1             26           1   unit12      76         27             52           3   unit13      76          1             26           2   unit14      94          1             26           4   unit15      39          1             26           2   unit16     188          1             26           2   unit17      58         27             52           1   unit18      48         27             52           2   unit19     137         27             52           1   unit20     469         27             52           4   unit21      52          1             26           3 ; table manpower(i,t) 'Manpower required for each week'         week1 week2 week3 week4 week5 week6 week7 week8 week9 week10 unit1    10    10     5     5     5     5     3 unit2    10    10    10     5     5 unit3    15    15 unit4    20 unit5    10    10    10    10    10 unit6    15    15    15 unit7    15    15    15 unit8    10    10    10     5     5     5 unit9     3     2     2     2     2     2     2     2     2     3 unit10   10    10     5     5 unit11   20 unit12   10     1     5    15 unit13   15    15 unit14   10    10    10    10 unit15   15    15 unit16   15    15 unit17   20 unit18   15    15 unit19   15 unit20   10    10    10    10 unit21   10    10    10 ;

Just to be sure I added some checks:

set error(i,t) 'check for mismatch between manpower and outage-weeks'; error(i,t)$(manpower(i,t)=0 and ord(t)<=data(i,'outage-weeks')) = yes; error(i,t)$(manpower(i,t)<>0 and ord(t)>data(i,'outage-weeks')) = yes; abort$card(error) "manpower mismatch",error;

Low and behold, we see:

----     93 manpower mismatch ----     93 SET error  check for mismatch between manpower and outage-weeks              week4 unit12         YES **** Exec Error at line 93: Execution halted: abort$1 'manpower mismatch'

Indeed we have for this unit a problem in the manpower allocation.