Vendor Evaluation/performance report

We need a report that shows vendor delivery performance. We wanna do that report by comparing GR date with Delivery date including delivery quantity between a specified time interval(for example september.2007). Report must check if supplier sends the parts on time.If supplier send parts, for example 4 days early, then system must find it comparing delivery date with actual good receipt date.And also order quantity must be compared with delivered quantity.This analysis must be done for schedule lines and POs all together.