How to Use This Tool
Accumulate user-measured leg variability and fixed facility delay without using live traffic. Estimate a delivery appointment buffer from route legs, measured per-leg variability, a confidence multiplier and fixed facility delay.
The decision this tool supports
A flat percentage buffer ignores how repeated uncertain legs accumulate and how a fixed dock or gate delay differs from travel variability. This page keeps the decision bounded to recommended planning buffer and the supporting outputs shown beside it. Delivery Buffer does not import an account, infer a market rate, or silently substitute an industry average.
Inputs and units
The Delivery Buffer calculation uses Independent route legs, Measured variability per leg, Confidence multiplier, Fixed facility uncertainty, Planned drive time. Keep all money values in one currency and all time, distance, mass, energy or volume entries in the unit printed beside the field. Mixing Delivery Buffer scopes can produce a plausible number with the wrong meaning.
- Independent route legs is entered in legs.
- Measured variability per leg is entered in minutes.
- Confidence multiplier is entered in standard deviations.
- Fixed facility uncertainty is entered in minutes.
- Planned drive time is entered in minutes.
Formula and worked check
Route uncertainty = sqrt(independent legs) × measured per-leg standard deviation × multiplier; total buffer adds fixed facility uncertainty. Four legs with 12-minute variability, a 1.65 multiplier and 20 fixed minutes yield a 59.6-minute buffer on a 180-minute drive. The Delivery Buffer default is an executable known-answer case, not a benchmark or recommendation. Change one input and verify that the direction of recommended planning buffer still matches the stated relationship.
How to interpret the result
Calibrate variability from comparable routes and treat correlation between legs as a reason to test a more conservative scenario. The additional Delivery Buffer outputs expose the denominator, comparison, capacity or reverse value needed to audit the primary result instead of presenting one unexplained number.
Assumptions
- Per-leg variability is a measured standard deviation.
- Route-leg deviations are independent for the square-root rule.
- Fixed facility uncertainty is added once.
Save the Delivery Buffer input values and date with any material decision. A later Delivery Buffer rerun is reproducible only when the same assumptions and units are available.
Limitations and safety boundary
It does not query traffic, weather, hours-of-service, border, terminal or appointment systems and assumes independent route-leg variation. Delivery Buffer is an estimate and cannot replace a contract, local code, licensed professional, calibrated measurement, lender statement or platform report where one governs the decision.
Source and privacy
The Delivery Buffer definition or rule was checked against NIST Guide for Conducting Risk Assessments on 2026-08-26. Recheck NIST Guide for Conducting Risk Assessments when a specification or policy behind Delivery Buffer can change. Delivery Buffer arithmetic runs in this browser tab; ecech does not receive the values through a calculation API.
Sources & assumptions
Tool Spec v2 · verified 2026-08-26. Platform rules and fees can change; the editable inputs remain authoritative for your account.
Official references
- NIST Guide for Conducting Risk Assessments (checked 2026-08-26)
Model assumptions
- Per-leg variability is a measured standard deviation.
- Route-leg deviations are independent for the square-root rule.
- Fixed facility uncertainty is added once.
- It does not query traffic, weather, hours-of-service, border, terminal or appointment systems and assumes independent route-leg variation.
