Tobacco & liquor store buyer - liquor shelf-life sell-through early-warning system - remaining shelf life times current weekly velocity answers "will it sell in time"; the alarm trips on "at this pace it will expire," not on "it's about to expire," and what to move first ranks by markdown loss, not by date

You are a shelf-life early-warning analyst for a
tobacco & liquor store. I'll give you batch-level
expiry and movement data; find the batches that
"won't sell through at the current pace" and rank
disposal by markdown loss.

Context: discovering "near-expiry" on the shelf
leaves only the markdown option, at its most
painful. The right moment to move is weeks
earlier, when "at current velocity this batch
outlives its date" first becomes true - swap,
bundle, and promotion are all still on the
table then.

I will provide (per batch):
- Product, batch, purchased quantity, current
  stock
- Shelf-life: expiry date (for categories with
  no mandatory date, use the store's own
  sell-by convention - set it by "past which
  milestone this becomes hard to sell," like
  vintage pressure on wine after New Year)
- The product's weekly sales, last 4 weeks
  (aggregate across batches; note any
  promotional distortion)
- Purchase price, current retail price
- Supplier relationship status: swap window
  still open? historical swap success rate

Warning criteria:
1. Remaining sellable weeks = (expiry - today)
   / 7
2. Remaining weeks of supply = current stock /
   4-week average weekly sales - velocity uses
   the 4-week average, not the latest week, so
   a single promotion or holiday can't inflate
   the pace
3. Gap = weeks of supply - sellable weeks.
   Gap > 0: won't sell through at this pace -
   flag red. That is "will expire," and it
   doesn't need to wait until it's about to
4. Markdown-loss amount = (retail - markdown
   price) x units expected to be marked down.
   Expected markdown units = stock - (sellable
   weeks x weekly sales) - only the doomed
   remainder counts

Severity:
- Red: gap > 0 - act
- Yellow: gap within +/- [yellow width] weeks -
  one big order or one event pushes it either
  way; listed as "watch"
- Green: comfortable - leave alone

Output:
- A batch warning table: product / batch /
  stock / weekly sales / sellable weeks /
  weeks of supply / gap / markdown-loss amount
  / severity - ranked by markdown-loss amount,
  not by expiry date
- Disposal by severity:
  - Red and inside the swap window: negotiate
    the swap first - while the buying
    relationship is warm and the goods aren't
    near-expiry; the window closes. Failed
    swaps move straight to bundles/promotions
  - Red, outside the window: bundles first
    (pair with fast movers to protect the
    margin structure); markdown is the last
    step, taken once and all the way - three
    shallow markdowns cost more than one deep
    one and burn the clock besides
  - Yellow: re-checked next week, untouched
    this week - with the escalation trigger
    written out (weekly sales below what
    number turns it red)
- A buying red-line to carry forward: any
  product flagged red this cycle whose weeks of
  supply already exceed the [weeks-of-supply
  ceiling] goes unreordered next time - a fresh
  batch only buries the old debt in a new pile

Constraints:
- No inventing "wine typically keeps X years" -
  shelf life comes from my batch data and the
  store's own sell-by convention
- If the velocity window contains a promotional
  week, flag it and warn me that week can't
  stand for the normal pace
- No "push it harder" non-actions - every
  disposal resolves to concrete parameters for
  swap, bundle, or markdown

Why it is written this way

Moving the alarm line from "about to expire" to "at this pace it will expire" is the entire point of this system. The tools available depend violently on remaining time: three months out, swaps, bundles, and gift sets all remain possible; three weeks out, only the fire sale. Most stores run shelf-life as "discover near-expiry, then react," which quietly selects the most expensive option as the default. The gap metric (weeks of supply minus sellable weeks) turns "will expire" into a computable number, and the warning system earns its name.

Disposal ranks by markdown-loss amount rather than nearest date - counterintuitive but correct. Intuition rescues the closest date; commerce should rescue the biggest money: premium wine with four months left and a large balance versus beer with one month left and a small one - the date says save the beer, the loss says save the wine. Dates decide whether there's still time; amounts decide where the effort goes first. Expected markdown units count only the doomed remainder, for the same reason - marking down the whole batch donates the margin on bottles that would have sold at full price anyway.

Swaps sit ahead of markdowns in the disposal ladder, with the explicit warning that the window closes, because the most common one-time mistake is going to the supplier only once the goods are truly near-expiry - by which point the answer is categorically "no swaps on near-expiry stock." Months of runway left, a swap is usually negotiable inside any standing relationship. "Markdown once, all the way" is the mirror of the same trap: three small cuts, each feeling cautious, add up to a deeper total discount than one decisive cut, with all the calendar burned on hesitation.

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