An OTIF calculation measures the share of orders delivered both on time and in full, while fill rate measures how much of the ordered quantity or how many order lines were shipped. OTIF is the stricter score: an order that is late or short counts as a miss, however close it was.
What is the difference between fill rate and OTIF?
Fill rate looks at quantity, and OTIF looks at whole orders. Fill rate asks how much of what was ordered got shipped. OTIF asks what share of orders arrived inside the agreed window with nothing missing.
That difference matters because the two can tell opposite stories about the same period. A supplier can ship 97% of the units ordered and still deliver far fewer than 97% of orders perfectly, since small shortages and late arrivals are spread across many orders. Customers who receive their orders feel the OTIF number, not the unit fill rate.
The formulas
These definitions match the fill rate and OTIF calculator. Each is a count divided by a total, for a defined period.
OTIF = orders delivered both on time and in full / total orders
- On-time rate = orders on time / total orders
- In-full rate = orders in full / total orders
- Line fill rate = lines filled completely / lines requested
- Unit fill rate = units shipped / units ordered
Customers often define the delivery window and what counts as in full, so use the definition in your agreement. If a retailer measures against the requested date and you measure against the promised date, you will be reporting different numbers for the same deliveries.
Worked example
The figures are illustrative. In one month a distributor has 1,000 orders due. Of these, 940 arrive on time, 960 are complete and 905 are both. Across all orders there are 5,000 lines, of which 4,850 were filled completely, and 120,000 units were ordered with 117,000 shipped.
- On-time rate = 940 / 1,000 = 94.0%.
- In-full rate = 960 / 1,000 = 96.0%.
- OTIF = 905 / 1,000 = 90.5%.
- Line fill rate = 4,850 / 5,000 = 97.0%.
- Unit fill rate = 117,000 / 120,000 = 97.5%.
The result: the headline fill rates look excellent at 97% and above, yet one order in ten missed the OTIF standard. Both statements are true, and the gap is the useful finding.
Why can OTIF be lower than both on-time and in-full?
OTIF can be lower than both because an order has to pass two tests at once. Orders that are late but complete, and orders on time but short, are both misses. In the example, 940 orders were on time and 960 were in full, but only 905 were both, so the overlap is smaller than either group.
A quick check is that OTIF can never exceed the smaller of the on-time and in-full counts. If a report shows it higher, the data or the definitions are inconsistent.
Which fill rate should you use?
Choose the version that matches the decision. The table compares the common options.
| Measure | Counts | Best for | Weakness |
|---|---|---|---|
| Unit fill rate | Units shipped / units ordered | Inventory and supply planning | Hides many small shortages |
| Line fill rate | Lines complete / lines ordered | Warehouse and pick performance | A line short by one unit counts as a full miss |
| Order fill rate | Complete orders / orders | Customer experience | Harsh on large multi-line orders |
| OTIF | Orders on time and complete / orders | Customer scorecards and contracts | Depends heavily on the agreed window |
How do you read and improve the result?
Look at the gaps between measures to find the cause. A low on-time rate with a high in-full rate points to transport, scheduling or dock appointments. A low in-full rate with a high on-time rate points to inventory, planning or picking. Late and short together often means upstream supply failed and the order shipped late to wait for stock.
Break the numbers down by customer, product family, warehouse and carrier, and track them over time. A single blended percentage can hide one carrier or one customer account dragging the average. Short deliveries usually trace back to forecast error and buffer sizing, so the demand planning guides and the logistics and transportation guides are the natural next reads.
Traps that make delivery scores misleading
- Measuring against the date the warehouse chose rather than the date the customer requested.
- Counting a delivery as on time when it left the dock on time but arrived late.
- Letting a customer’s tolerance (for example, short by a few units) differ from what the report assumes.
- Excluding backorders or cancelled lines, which makes fill rate look better than the customer experienced.
- Mixing order, line and unit denominators in the same report.
- Comparing OTIF between customers who define “on time” differently.
- Reporting only the average when one account or lane drives most of the failures.
Limits of the measures
OTIF treats all misses equally. An order one hour late and one three days late both count the same, as do an order short by one unit and one short by half its quantity. If those differences matter, add measures for days late and shortage size alongside OTIF. Also remember that a high score can be bought with extra stock and expedited freight, so read it next to inventory and transport cost.
Where analytics helps
Analytics is useful for finding patterns in misses, such as particular lanes, days of the week or product families. Predictive models can flag orders at risk of being late or short before shipping, so planners can act. They rely on clean timestamps and consistent definitions, which is where most of the effort goes.
Common questions
What is the difference between fill rate and OTIF?
Fill rate measures the share of ordered quantity or lines that were shipped. OTIF measures the share of whole orders that arrive on time and complete. OTIF is the stricter measure, because a single late or short order counts as a miss even if most of the goods arrived.
What counts as on time?
On time means inside the delivery window agreed with the customer, which may be a date, a time slot or a number of days. Use the customer’s definition for customer reporting, and apply one consistent definition across customers when comparing internally.
Why can OTIF be lower than both on-time and in-full?
An order must meet both conditions to count. Orders that are late but complete, and orders on time but short, are both misses. The orders passing both tests are only the overlap of the two groups, so OTIF cannot exceed the smaller of the two rates.
Is a higher fill rate always better?
Not at any cost. Pushing fill rate toward 100% usually needs more safety stock, faster freight or both. Set targets by item importance and compare the cost of shortages with the cost of extra stock, so service is bought where it pays back.