BOM-With only one compnant qty changes

Hi,

I create a BOM as under:-

BOM Name Wire rope sling Double legged

using component

wire rope 2.6 mtr ( assuming FG for length of 1 mtr)

Ferrule 2 No NO CHANGE

Thimble 2 no NO CHANGE

eye hook 1 no NO CHANGE

Ring 1 no NO CHANGE

Now if I want to make SAME bom FOR 2 MTRS

THEN only my first component i.e. wire rope qty changes to 4.6 mtr i.e. additional two mtr require to make length of two mtr ( ratio of 1:2)

all other component remain un-changed so my BOM Name Wire rope sling Double legged for 2 mtrs will use following component

wire rope 2.6 mtr+2 ( assuming FG for length of 2 mtr)

Ferrule 2 No NO CHANGE

Thimble 2 no NO CHANGE

eye hook 1 no NO CHANGE

Ring 1 no NO CHANGE

like wise for example for 5 mtr length for same BOM only 10 mtr ( ratio 1:2) will added in base qty of 2.6 mtr and again all other component will remain un-changed.

Is this possible by using batch or run- query or have any other solution to avoid end number of BOM of same category.