Can anyone explain the random component placing?

[Suicide Junkie]

In the ship design, wanted comps.

You choose the component name you want, where it goes, and the chance of choosing it for any particular ship.

After you have the basic components, weapons and defenses placed, there will be some space left over, say 20kt.
In order to keep some variety, you can for example, place a shield regenerator with a 50% chance, and then an afterburner with a 100% chance.
Half the ships will have a regenerator... Those that do will have no space remaining and be finished. Those that didn't add the regenerator will still have space to fill, and an afterburner will be placed instead.