Failed Delivery Rate

A courier takes 100 parcels out for first delivery attempts and cannot complete 12, so the first-attempt failed delivery rate is 12% for those attempts, which is not the same as the final undelivered-shipment rate. Choose the unit first: an attempt-based rate counts delivery attempts while a shipment-based rate counts distinct shipments whose first attempt failed, and a parcel attempted three times could distort comparisons if the units are mixed.

Set what counts as success too, because handover to the named person, safe-place delivery, a parcel locker deposit and proof of delivery may be treated differently by service and contract, so record the standard before comparing carriers. UPS explains that its delivery notice is left when an initial delivery or pickup attempt is unsuccessful, a concrete operational event that differs from a parcel permanently lost or returned.

AfterShip's shipment analytics describes exception-rate calculations and first-attempt timing measures, but its metrics are related and not interchangeable with a custom failed-delivery formula. Possible causes include missing address details, recipient absence, inaccessible buildings, incorrect contact information, payment or customs issues, weather and carrier operational problems, so do not assign every failure to the customer.

Separate preventable and unavoidable causes, since an incorrect apartment number invites checkout validation while a regional storm needs a different response, and a single overall percentage hides both. Use a defined period by counting eligible first attempts scheduled or made in a week and failures among that same cohort, because comparing this week's failures with this week's total shipped orders can mismatch timing.

An illustrative first-attempt failure rate is failed first attempts divided by all eligible first attempts times 100, so twelve failures out of 100 first attempts gives 12%. Check events before finalising the numerator, because a scan marked "delivery attempted" may later be corrected and carrier codes can differ, so reconcile exceptions to proof of delivery and customer reports where practical.

Watch multiple parcels per order, since one customer order can have two shipments, only one of which fails, and the metric must be defined per parcel, per order or per attempt. Segment by route, carrier and address type, because apartment buildings with restricted access can differ from staffed business premises and raw carrier comparisons may be unfair if one handles more difficult routes.

Measure redelivery cost, since a failed attempt may trigger another trip, customer contact, storage or return, and the cost is not necessarily equal across failure reasons. Connect delivery windows to expectations: a customer who was told a narrow window may be more likely to receive the parcel than one given an uncertain date, but do not claim causation from one simple comparison.

Improve address quality at checkout by confirming postcode, unit number, contact number and delivery instructions while respecting privacy and retaining only what is needed, and offer appropriate options such as a collection point, time selection or address correction, remembering that not every package is eligible for every option. Communicate quickly after a failure by telling the customer the next carrier step, available choices and any deadline for collection, because an automated "delivered" message on a failed attempt makes the problem worse.

Keep return-to-sender separate, since it may follow repeated unsuccessful attempts or a refusal but the first failure and final return are different milestones, and compare trends with volume because two failed attempts out of ten is 20%, a noisy rate, so report the count and denominator alongside the percentage. For owners, failed delivery rate is a diagnostic, not a verdict: a useful metric states the unit, eligibility, event window and final status, then leads to fixes for the causes the business can control.