The main purpose of the Historical Inventory Stock Status report is to show what inventory quantities and values were at certain points in the past. For example, if I wanted to see what my exact inventory quantities/values were on April 1st, 2009, I could select April 1st, 2009 as the End Date of the report, and the report would calculate my exact inventory quantities (and their respected values) as of April 1st, 2009.

Here are some bullet points regarding how the report actually calculates the data that you are seeing:

• The report uses the Post Dates of transactions to determine when inventory quantities changed
• Only inventory tracked items appear in the report
• If an item/location combination had 0 quantity on the selected End Date, then the combination won't appear on the report
• The Average Cost column shows the row's Inventory Value divided by its Quantity.
• The list of inventory in and out records which the report uses is similar to what is shown on the Item card's Inventory Movement tab. The main difference being that the Inventory Movement tab does not show location, while the report shows quantities and values per item/location combination
• The report calculates each item/location combination's Inventory Value for the present time by multiplying one of the item/location combination's costs with the item/location combination's quantity. The item's Valuation Method determines which cost the report uses
• The report calculates historical Inventory Value by taking the present time's Inventory Value and subtracting each reverted transaction line item's Extended Cost (Unit Cost multiplied by Quantity)

Something else to keep in mind when viewing the report is that you may encounter a negative value. While item/location combinations generally shouldn't have negative quantities (since that would suggest that the item had a negative quantity on-hand at some point), it is still possible for this report to show negative quantities. Considering that you are able to manually select a Post Date on a transaction, if the Post Dates of transactions aren't in the order that they actually happened, you may encounter a negative value.

For a more technical look at how the report works;

When generating the report, the server looks at the inventory quantities and values at the present time, then the server looks at a list of inventory in and out records (which show every time that a transaction changed an item's quantity). The server takes every posted transaction, with a Post Date greater than the selected End Date, and reverts their changes to the present time's inventory quantities and values. In doing so, the end result shows what each item/location combination's quantity and value was at the end of the day of the selected End Date.