'Qty On Hand' is the field in Paradigm that displays the total quantity that the Company realistically owns at present.
As this is a true physical stock holding, Paradigm does not allow this figure to run below zero.
Paradigm calculates theoretical stock quantities based on Sales Orders, Purchase Orders, Production Tickets and other transactional documents. This 'Qty Available' field is allowed to run into negative. To view the full 'Qty Available' calculation, see Inventory Quantity Buckets.
EXAMPLE
In the image above you can see that 20 000 stock has been loaded onto an Invoice.
'Qty On Hand' is 15 069 and 'Qty Available' is 35 064.
Paradigm will prevent this Invoice from being 'Posted to Financials' as the 'Qty On Hand 'is not sufficient for this transaction.
The Invoice can only be 'Posted To Financials' once there is enough stock in 'Qty On Hand'.