When to put pull-ups into a workout?

[Diablo10000]

I love doing pull-up for some reason. I have been doing them on back and bis day. Is this good or should i do them on another day when im training another part of the body.

P.S. I always do them after im done working out to really get a burn.

[guest589745]

I do em at the end of my back workout when I am somewhere that has a bar, to failure.