An Efficient Heuristic Approach for Irregular Cutting Stock Problem in Ship Building Industry

Algorithm 4

Combinations of 3 items.

(4.1) for  each   do

(4.2)     if  free area of stock sheet − area of the item   − area of the two largest item’s area > percentage

      then

(4.3)     break

(4.4)     if  item does not fit  OR  area of item smallest items’ area > free area of stock sheet  then

(4.5)     continue

(4.6)     if  this item could not be placed  then

(4.7)     record the item that could not be placed

(4.8)     else  select a second item

(4.9)     for    do

(4.10)          if  free area of stock sheet − area of item and   − area of largest item > percentage  then

(4.11)          break

(4.12)          if  item or the combination of item and do not fit

              OR  area of item and + area of smallest item > free area of stock sheet  then

(4.13)          continue

(4.14)          if  this item could not be placed  then

(4.15)          remove the first item   AND  record the combination of item and that does not fit

(4.16)          else  select a third item

(4.17)      for  each   do

(4.18)               if  free area of stock sheet − area of item , and > percentage  then

(4.19)               break

(4.20)               if  any item, or combination of two items or combination of the three items does not

                     fit  OR  area of item , and > free area of stock sheet  then

(4.21)               continue

(4.22)               if  the item could be placed  then

(4.23)               return

(4.24)               else  remove first 2 items  AND  record the combination of 3 items that does not fit