Magento 2 Multi Source Inventory is a useful feature that's been released with Magento 2.3. You can not only create Magento sources and add them to stocks but also track the salable quantity and manage the number of products available for purchase.
But what is the salable quantity and how does it differ from the quantity per source? These two terms may seem a little bit confusing, but in this article, we'll explore these questions and clear everything out.
What is Salable Quantity in Magento 2?
Magento salable quantity is the sum of all products from all your sources. It decreases when an order is placed. However, when somebody cancels an order, products are added back to the salable quantity. In other words, salable quantity reflects the number of all items you can sell.
You can see an additional column — Salable Quantity — near the Quantity per Souce column while working with the product grid (Catalog > Products).
Magento 2 Salable Quantity vs Quantity per Source
The main difference between salable quantity and quantity per source is that quantity per source doesn't decrease when an order is placed. Quantity per source remains stable until the order is shipped, while salable quantity reduces right after a customer's places an order.
Let's consider an example. For instance, you have a Default source (quantity per source: 10 items) and a Second source (quantity per source: 3 items). They are organized into the Default stock (salable quantity: 13 items).
A customer places an order for 9 items. This is why you will have:
Default stock (salable quantity: 4 items) = Default source (quantity per source: 10 items) + Second source (quantity per source: 3 items)
After the shipment, you will see the following numbers:
Default stock (salable quantity: 4 items) = Default source (quantity per source: 1 items) + Second source (quantity per source: 3 items)
As you can see, after the order placement only the salable quantity got decreased (from 13 to 4 in our case). And only after the shipment, we could see a change in the quantity per source (from 10 to 1 in the Default source).
That's why salable quantity is a useful feature of Magento MSI. It allows you to have a broader image of your current inventory so you won't run into any out-of-stock situations.