oracle Purchasing Literacy

hi friends ... i have one question in my mind that disturb me alot ... the question is that oracle has provided a standardrized method of purchasing and this method is really good no. doud about it ..... but i have seen the organization / business units where Oracle ERP has implemented they are not getting the fruits of it and they are just following the same procedure as they were before .... i am working in a client where we used to make the requisition of part after purchasing verbally ............
here comparitive statement of items has made after invoce of an item is receive .........