Minimum remaining shelf life is the least amount of time a wholesale buyer will accept on your product's date when it arrives at their door. It's written into the vendor agreement either as a number of days ("at least 30 days to the best-by date at delivery") or as a share of the product's total shelf life ("at least 75% remaining at receipt"). To meet it, work backward from each lot's date: latest delivery date = best-by date − the buyer's minimum days. Anything older goes to customers without a rule, like your own shop or the market.
The short version
- Get each buyer's rule in writing, in days or as a percentage, and whether it's measured at shipping or at receipt.
- Turn percentages into days: minimum days = total shelf life × the percentage.
- For every lot and every buyer, work out the last day it can arrive. Ship before that, allowing for transit.
- Send the freshest lots to the strictest buyers and older lots to customers without a rule.
- TaroStack keeps each customer's rule on their account and picks the right lot by it. More below.
Why buyers ask for it
A distributor or a grocery chain has to sell your product on to someone else before the date runs out: from their warehouse to a store, from the store shelf to a shopper, and the shopper needs time to eat it. If your pouches arrive with three weeks left, they'll be pulled from the shelf unsold, and the buyer eats the cost, or sends you a deduction. The rule protects them from that. The stricter the rule, the longer their chain.
So the numbers vary by customer. A café buying bread for tomorrow might want two days. A grocery chain might want a month on chips. A distributor selling into many stores might want most of the shelf life still there. There isn't one standard to look up, which is exactly why it has to be in writing for each one.
The formula
Days left at delivery = best-by date − delivery date
Share remaining = days left ÷ total shelf life
Minimum days (from a %) = total shelf life × required share
Latest delivery date = best-by date − minimum days
Latest ship date = latest delivery date − transit days
A worked example
Windward Roots, the made-up taro business I use in these examples, makes taro chips with a 90-day best-by date from packing. It sells to three kinds of customer:
| Customer | Their rule | In days | Chips must arrive within |
|---|---|---|---|
| A grocery chain | At least 30 days left at delivery | 30 | 60 days of packing |
| A distributor | At least 75% of shelf life left at receipt | 67.5, so 68 | 22 days of packing |
| Own shops and the market | No rule | 0 | Any time before the date |
On September 30 there are two lots at the warehouse:
| Lot | Packed | Best by | Days left on Sep 30 | Share left | Grocery chain (30) | Distributor (68) |
|---|---|---|---|---|---|---|
| C260901 | Sep 1 | Nov 30 | 61 | 68% | Yes, until Oct 31 | No |
| C260922 | Sep 22 | Dec 21 | 82 | 91% | Yes, until Nov 21 | Yes, until Oct 14 |
Read across the rows. The older lot can still go to the grocery chain for another month, but it can't go to the distributor at all: it was already under 75% a week ago. The newer lot can go to either, but only until October 14 for the distributor. If the distributor's warehouse is two days away by truck, the last day to ship it there is October 12.
So the right picking for this week's orders isn't oldest-first. The distributor gets the September 22 lot, the grocery chain gets the September 1 lot while it still qualifies, and anything left of the older lot goes to the shops and the market, where it'll sell long before November 30. That's still first-expired-first-out, filtered by who's receiving it, and it's the same idea as the example in FEFO vs FIFO.
Plan production around the strictest buyer
The rule reaches back into the kitchen. If a distributor needs 68 of 90 days, nothing for them can sit in the warehouse for more than three weeks, so making a big batch once a month won't work for that customer even if it suits the fryer. Three things help:
- Make for strict buyers close to their delivery day, in smaller batches if you have to.
- Keep a lot ready for each rule: a fresh one for the strict buyers, and let the older one flow to the lenient ones.
- Put the delivery day for each buyer on the production calendar, worked backward from their rule, the way the production schedule example works backward from orders.
And check the date you print. If your shelf life is longer than the date you've been printing out of caution, you're giving the rule away for nothing; if it's shorter, the rule is the least of your problems. How dates are written on the package is covered in how to create lot numbers, which uses the packing date in the code.
Questions to ask before you sign
- Is the minimum measured when it leaves you, or when it arrives at their dock?
- Is it days to the best-by date, or a percentage of total shelf life? If a percentage, which shelf life: the one on your spec sheet?
- What happens to a delivery that's short: refused, accepted with a deduction, or accepted this once?
- Does the rule change by product?
Write the answers on the customer's record. A rule that lives in one person's head fails the week they're off.
Where this stops working
On paper this is a lookup: a table of customers and their days, and the lots with their dates. It breaks at the dock, on a busy morning, when whoever is picking reaches for the front of the shelf, which is the oldest lot, which is the one the distributor will refuse. It breaks when the rule changed in the spring and the sheet didn't. And it breaks in planning, because nobody re-checks whether the batch being made today will still qualify by the time it ships.
How TaroStack does it
In TaroStack the rule is part of the customer, so nobody has to remember it. You record each customer's minimum days of shelf life on their account, and when an order is picked, the stock comes from the lot that expires first among the lots that still meet that customer's rule. The distributor gets the September 22 lot, the grocery chain gets the older one while it qualifies, and the market gets what's left, without anyone working out a table at the dock. Lots carry their packing and best-by dates from the moment they're made.
Planning knows the rule too. A batch made too early for a customer's minimum days-left is flagged before you make it, so the big monthly fry that would miss the distributor's window shows up as a problem on Monday, not as a refused pallet in three weeks. And the expiring-stock forecast shows what's heading for its date unsold, and what it's worth, while there's still time to send it to a customer without a rule.
Lots, expiry and customers' shelf-life rules are on every plan, from $49 a month; planning is on Standard at $99. The first 30 days are free, and your customers and lots import from a spreadsheet. If you'd like a hand setting up, ask, and we'll do it with you.