What it means
A store's system may show six units of a product while the display shelf is empty, so customers cannot take one from the shelf. On-shelf availability, or OSA, asks what the shopper can actually buy.
Crisp distinguishes shelf availability from a general in-stock system figure, because stock may be in the backroom, misplaced or inaccurate in the record. For a spot audit, check the products meant to be carried in a particular store.
If 970 of 1,000 eligible store-item checks find a buyable product on the correct shelf, the illustrative OSA is 97%, which describes those checks and not every minute of the month. A time-based measure can instead estimate the share of selling hours an item was available, but it needs repeated observations or reliable event data and should not be combined with a spot-check percentage without labelling the method.
Gaps have several causes. A fictional supermarket's cereal sits in a delivery cage but not in the aisle, so its inventory balance looks positive while the shelf check fails, and the fix is replenishment, not a new supplier order.
Other gaps come from incorrect locations, damaged goods, a wrong price label or an unrecorded stockout, so diagnosis should identify the cause before ordering more stock that may already sit in the back. SPS Commerce discusses the limitations of manual checks, inventory records and sales-based estimates.
A system balance alone may create phantom availability, and a lack of sales alone does not prove a shelf was empty. A fictional stationery chain sees low sales on one notebook size, finds the stock behind another item on a store visit and restores shopper access by correcting the placement, without changing total inventory.
Define which items belong in the denominator, because a product deliberately removed from a store's assortment should not count as unavailable forever and promotions and seasonal displays need a stated rule. A simple percentage treats slow and high-demand sellers equally, so a weighted view may focus action if its basis is reported.
Audits run only after restocking can mislead, so vary store and time samples around ordinary shopping patterns and record the date and location of each observation. Images or shelf sensors may help scale checks, but they can misread packaging, price labels or occluded products, so review exceptions against a physical check.
An item can also be on the shelf but unsaleable, since a damaged package or blocked display fails a shopper-focused check, which is why buyable matters more than merely visible. OSA does not measure customer satisfaction by itself, and no universal target applies because product mix, store format and measurement methods differ; track recurring gaps by store, item and cause, assign an owner for each problem and verify the product is buyable afterwards.
In practice
Real-world examples.
Example
A hypermarket audits 1,000 eligible shelf checks on a weekday afternoon and finds a buyable item in 970 of them, so spot-check OSA is 97%. The report states the date, the stores visited and the assortment list used. Management does not claim the same figure holds for weekends.
Example
A pharmacy chain's system shows six units of a vitamin product, yet the display shelf is empty because the cartons are sitting in the stockroom. The inventory record looks healthy, but a shopper cannot buy the item. A restocking routine, not a new order, closes the gap.
Example
A convenience store passes every morning shelf check but sees repeated gaps after the evening rush. A late-day audit reveals the stockouts, and the manager moves a replenishment run to mid-afternoon. The daily average had hidden the peak.
Formula
Calculation
Spot-check OSA = eligible store-item checks with the item buyable on shelf / all eligible store-item checks x 100. State the sampling time and assortment rules.
Worked example. A fictional grocer audits 1,000 eligible store-item combinations on a Tuesday afternoon and finds a buyable product on the correct shelf in 970 of them. OSA = 970 / 1,000 x 100 = 97%. The 30 failed checks are then sorted by cause: if 18 are product in the backroom, 8 are wrong locations and 4 are true stockouts, 26 of the 30 gaps (87%) are fixed by better replenishment and shelf discipline rather than by ordering more stock.Case study
Seen in the real world.
In this fictional example, Bright Snacks sees positive store inventory but disappointing sales. Checks reveal that several shops leave delivered boxes in the backroom, so the shelf is empty even though the record shows stock. The retailer changes its replenishment routine and repeats shelf checks across times and stores.
It does not treat inventory records alone as proof of availability, and it records the cause of each gap rather than counting misses as one total. Bright Snacks also discovers that its flagship-store audits look much better than those of smaller outlets, so it widens the sample before reporting a network-wide figure. The case is invented, and a routine change does not guarantee any particular result.
Watch out
Common mistakes.
- Equating system stock with a buyable shelf item.
- Auditing only after scheduled restocking.
- Counting discontinued items in the expected assortment.
Questions
People also ask.
Can sales data alone measure OSA?
It can suggest gaps but may not prove whether a shelf was empty.
What belongs in the denominator?
Items expected to be sold in the defined stores and sampling period.
Is online availability the same?
No. Online fulfilment has different availability and delivery conditions.
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