Does anyone know in DBA what constitutes a "Period" in the average cost calucaltion of inventory.  We have had a couple of negative transactions on some of our parts and the average costs seems to be way off from what we think it should be.  Does DBA go back to the first purchase of that particular item, or does it just go back one year? one month? or does it go back to when that particular inventory was at zero levels.  Please advise.
 

The negitive transactions are for instance:
Pounds of steel plate received incorrectly and then un received and wrong amount then re-recevied at correct pounds. If you look in transaction history it shows the in and out of this transaction but it seems to mess up the average cost calculation?  Shouldn't it have returned the average cost to the prior of this entry with the two transactions of in and out balancing each other out and then the new re-entry would calculated the new average cost.  Hope you understand what Im trying to say here?

the "period average cost" if you are referring to what is on the IN-E print Inventory transaction report, is the Period for the Date Range you've selected.
 
hence, if you leave the date range blank so it's all inclusive, then it will give you an Average Cost for the entire life of that Item. if you've selected a shorter time frame, then it's the Average Cost within that time frame.
 
this Period Average cost is different in that respect than your normal Average Cost, so you can actually use it for realizing a trend.
 
hth