A320 apu bleed usage in engine failure

[bigy]

Hi to all,

I have a question to you all. in the engine shut down cl we see that if the eng 1 fire p/b is pushed we use apu bleed with xbleed at shut position.
what is the reason that we use apu bleed? What happens if I donīt use apu bleed. Only thing that I can think of is go-around performance.

thanks