Generally this is not directly connection biee but so important for bi architecture,it likes a bone for structure,now lots of company use bi solution for repoting and different something but this is not generally structure form .In fact that ,i want say about why important on the figure ,When i saw the figure,i understood better
Now we can see that several thing but you can see Report and publishing side ,however system have several items on this picture.Now bi publisher make
Financial reporting
interactive repoting
sqr production reporting
web analysis
all of them are base of architecture for bi publisher 
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