Gaps still exist between vision and reality for EDI 852 data

In a recent conversation with a well known CPG vendor, it became very clear that vendors are still confused by data quality when it comes to EDI 852. Simply put, vendors are struggling with the known and unknown data quality issues that exist with the data retailers send out via EDI 852. Specifically, vendors are increasingly aware that on-hand inventory levels reported in EDI 852 are often suspect at best.
 
This vendor asked a very pointed question; "Why can't retailers get this right, and more importantly, how do they expect us to make decisions on bogus data?" This is a serious challenge and one that needs to be addressed by retailers. If they expect vendors to monitor in-stock and make accurate decisions, the data quality must improve. Fortunately, there are strategies to improve upon the data reported by retailers in order to arrive at a useful decision making tool.
 
First, each vendor has an accurate count of how many units the retailer purchased and they know when the inventory is to be shipped. By subtracting the units sold as reported in the EDI 852 from the shipped inventory units, you can calculate an on-hand value. The key to this work-around is a good starting point. In most cases, this can be determined by examining inventory history and requesting from the retailer a one time inventory position count. It's not a perfect system, but over time, the calculated on-hand becomes more and more accurate and it is a useful decision making tool. There are other strategies as well, but we see this as the most common method for handling poor on-hand reporting accuracy.
 
What strategies are you using to deal with poor data quality?  More importantly, what retailers are you working with that are not reporting accurate on-hand?  Many times, the starting point is simply identifying what data you can trust and what data you can't.