Determine influence factors

Thiru

dear all, 

while going through the  process steps of 'predictive maintenance',
 
step 2: is  to ' determine influence factors'.   

Im not able to realise the importance of the above step, as it seems it does not have any role
in predicting the classes of retrieved new data. 

what is the importance of this factor? and any article/video reference to this/

regds
thiru