The benefits of stock control are numerous:

• Allow you to know what you have in stock, for accounting purposes
• Allow you to know when to re-order items
• Prevents customers from purchasing items that are out of stock

At its simplest, stock control starts off with you identifying a numeric field in the product Form that represents the quantity in stock.

This can then be used by the Queries that display the products; so they might only show items with one or more in stock.

However the e-commerce system builds on this simple show/no-show switch, and adds on the abiliity to:

• Adjust the stock quantity down when a purchase is made.
• Prevent in-cart quantity changes that overshoot the available stock.
• Treat items in a customer's cart as not available for other customers to purchase.
• Return items from abandoned carts back into stock.

Note that with the final two items, the underlying stock field in the product Form is not adjusted whenever an item is placed in, or removed from, a cart. However the 'available to purchase' quantity that can be displayed to customers, and which is used for availablility purposes, is adjusted.

Other uses

Stock control can be used for traditional physical goods, or can be used for other items where there is limited supply, for example tickets to an event. It can also be used where you want to give the first so many people a discount, and then charge the item at the normal higher price.