Example view of Quantity per Source and Salable Quantity for a product:

Name	Quantity Per Source	Salable Quantity
Product X	Warehouse X: 100	UK: 185
	Dropship A: 50	DE: 180
	Dropship B: 20	AT: 180
	Dropship C: 10	CH: 180
	Dropship D: 0
	Brick store: 5

Explanation (Quantity per Source)

• This particular store setup uses separate Websites and Store Views per locale
• The Salable Quantity for each locale combines stock from Sources which have been set for that locale
• In this example, UK ships from every Source, so 100 + 50 + 20 + 10 + 5 = 185
• The other stores ship from everything except the physical store, so 100 + 50 + 20 + 10 = 180

After a customer orders 1 Product X from the AT store, but before it has been shipped:

Name	Quantity Per Source	Salable Quantity
Product X	Warehouse X: 100	UK: 184
	Dropship A: 50	DE: 179
	Dropship B: 20	AT: 179
	Dropship C: 10	CH: 179
	Dropship D: 0
	Brick store: 5

• This reservation reduces Salable Quantity by 1 for all stores connected to the same Source
• If Out of Stock Threshold has a positive value, it is subtracted from Salable Quantity

After the order has been shipped:

Name	Quantity Per Source	Salable Quantity
Product X	Warehouse X: 99	UK: 184
	Dropship A: 50	DE: 179
	Dropship B: 20	AT: 179
	Dropship C: 10	CH: 179
	Dropship D: 0
	Brick store: 5

• Now that the order has been shipped, the reservation is removed and the stock is reduced
• The stock is reduced at the Source which is the highest priority in the configuration and has stock
• Reservations which do not lead to shipments (order cancelled, for example) are removed once daily

Out of Stock Threshold setting

Products -> Catalog (under Inventory) -> Product X -> Advanced Inventory (under Quantity):

Formula

Salable Quantity = Source A stock - Reservations + Source B stock - Reservations (and so on in case of more Sources) - Out of Stock Threshold setting.