The definition
On-shelf availability (OSA) answers one question: can a shopper buy this product right now, from the dark store that serves them? In QComm each order comes from one nearby store, so OSA is measured store by store and rolled up to city and brand.
Two different problems
- Out of stock (OOS). The store lists the product but has no units. The shopper may see it and can't buy it. This is a replenishment or supply problem.
- Not listed. The store has never carried the product. The shopper never sees it there. This is a distribution problem.
They need different fixes, so measure them separately. Mixing them into one number leads to the wrong action.
Two ways to calculate it
- OSA across all stores in a city: of every store, how many have it in stock? This shows your true reach.
- OSA across listed stores: of the stores that carry it, how many have it in stock? This shows how well you keep the stores you are in supplied.
A product can score well on the second and poorly on the first, which means supply is fine but distribution is thin.
Weight by store importance
Stores don't sell equally. A gap in a busy store costs more than one in a quiet one. Weighting OSA by each store's sales gives a number closer to lost revenue than a simple count does.
Check OSA before blaming demand
When sales or market share fall, look at availability first. A drop that looks like competitors winning is often your own stock gap in a handful of stores. Fix that before changing price or ads. Ads in a store where you are out of stock don't sell.
How to track it
Seller portals show your own inventory. They don't show the shelf as shoppers see it next to competitors, store by store. Digital Shelf shows availability and listing gaps by dark store and city on Blinkit, Instamart and Zepto every morning. See also Blinkit data and why is my product not showing on Blinkit.