I want to monitor stock use. We entered stock levels for the first time on high theft risk products about 2 weeks ago. (These are small size, high price items like Advantix, Frontline, Revolution, etc). We obviously order in new product and want to tally up our product consumption based on vet stock supply data (from our vet supplier) and stock level (on computer) versus actual stock on hand. We would do this monthly.

1) How do we do this ?
2) If we modify stock levels, is a record of stock use stored in Open VPMS (or does it simply give a "snapshot" of what we have right now) ?
3) If there is a record of stock use how is it retrieved ?
For example if on March 20th we had 5 x Advantix 10-25 kg 6 packs and ordered in 10 on April 3rd (without adjusting stock level yet) , and the stock level is listed as -1, what do we do to update stock levels ? (This means when we do a stock take we should have 9 packs).