Delivery date instead of delivery window: how to promise a date that holds

“Expected 3–5 working days” is not a commitment but a hope. Here is how an estimate becomes a verifiable date.

The window is the problem

“3–5 working days” tells the customer one thing above all: we do not know exactly ourselves. Every day within the window is a day on which they wonder where their goods are — and a potential support ticket. A window is not a commitment; it is a hedged guess.

What a real promise needs

A specific date does not come from a rule of thumb but from four inputs: team capacity (how much can you handle per day?), order cut-off time (until when does an order count for today?), carrier transit (how long does the carrier need?) and public holidays (when is nothing delivered?). Calculate the four together, and “3–5 working days” becomes “Thursday, 22 May”.

The difference: verifiable

Naming a date is easy. Keeping it and being able to prove it is the point. Every promise is archived — with the capacity snapshot and the engine version on which it was calculated. When someone later asks “Why did you promise the 22nd?”, there is an answer, not an excuse.

Hit rate: the honest metric

A promise without measurement is marketing. The hit rate compares promised with delivered: how often did you keep the committed day? With a 12-week forecast, delivery reliability becomes plannable — and visible before it turns into a problem.

Why “deterministic” matters

Same inputs, same date — every time. No dice-rolling, no “a colleague would have judged that differently”. That makes the promise reproducible and thus verifiable in the first place.

How xl0g calculates this

xl0g Promise calculates the delivery date synchronously from exactly these inputs, archives every promise and measures the hit rate. Instead of a window, you get a date that you can give to the customer — and verify for yourself.

The business value

Delivery reliability is not a nice-to-have. A specific date that is kept reduces “Where is my order?” tickets, strengthens the repurchase rate and is often the tipping point in B2B. Anyone can say “3–5 working days”. A date that holds, not everyone can.

The first step

Have a Promise calculated for a typical order — you will see immediately how your capacity and transit data turn into a specific, verifiable date.

xl0g — Logistics without gaps. Knowledge over guesswork.