I have an answer: it’s either long enough or it isn’t.
Too short you have to either get another bit and tie it together or find a longer piece in the first place.
Too long and you can either cut some off or just not use the loose end.
Quite often it’s just perfect.
And my point? Well software is the same, whether you just spent a million or £200; if it fits the bill – great. Off the shelf and not use it all – fine (as long as it’s not too long). Integrate software components – fine.
One big difference in software is that the job itself can expand after you have tied it up – or even while you are tying it up! So the answer becomes: it’s long enough with some spare. And it’s important to know how much spare.
Of course you could also use cable ties, plastic coated steel wire, ribbon or tape …