APO as stand alone?

Hi

As of now SDP94,SNP94,rrp3   rrp_snp2ppds,   are the most used transactions - this apart mc90,mc62,rrp4,-----ppl1 for report ----and for ppds--  cdpso,cdpsb1, these are the transactions i use to generate a production plan .

APO is sufficient enough for me to do a production plan,Can i do away with R/3 ,because we are paying  license fee for R/3 and APO seperately.we can save costs.because for a production plan i need planning objects (master datas) that ca be set in CVC.and use APO alone.

I may sound funny from experts point of view ;though i havent come across APO as stand alone system.wish experts view on this .Can APO  stand alone??