A cold-chain indicator needs a defined scope as well as a name. State whether you are comparing products handled in the same week, completed incident records or a specific group of containers. Fix the example definitions below against your operation's data sources.
1. Temperature compliance: separate missing records. A valid record matches the correct shipment and sensor, covers the required transport interval and follows the defined measurement method. Calculate how many assessed shipments meet the temperature criterion. Show record coverage alongside it: shipments with valid records divided by all shipments. This measures the defined temperature criterion; it does not establish that a product meets every acceptance condition.
| Indicator | Example calculation | Missing data / owner |
|---|---|---|
| Temperature compliance (%) | Shipments meeting criterion / shipments assessed with valid records × 100 | Keep missing records separate; quality |
| Companion record coverage (%) | Shipments with valid records / all shipments × 100 | Separate missing files and sensors; operations |
| Mean response time (minutes) | Sum of first intervention minus alarm time / incidents with both timestamps | Do not count missing times as zero; incident owner |
| Product loss (%) | Unusable product kg / handled kg in the same product group × 100 | Code unknown causes separately; quality |
| Mean container cycle (days) | Sum of completed cycle durations / number of completed cycles | Report open cycles separately; container operations |
| Container loss (%) | Confirmed lost containers in the selected group / initial group count × 100 | Separate customer, transit and repair statuses; inventory |
A hypothetical example with 100 shipments. Suppose 90 of 100 shipments have complete records, of which 87 meet the temperature criterion and three show excursions. Record coverage is 90/100 = 90%; compliance among assessed shipments is 87/90 = 96.7%. The remaining ten are unknown. Report all three groups together: 87 compliant, three with excursions and ten unassessed.
2. Acknowledgement, intervention and closure have separate times
Record the alarm, acknowledgement, first intervention and incident closure separately. The table's response time is first intervention minus alarm time; it is not the time to product disposition. Review the longest response and open incidents alongside the mean. FAO/WHO §19.10 supports reviewing corrective-action records for trends and effectiveness.
3. Use the same product group for product loss
If you track a group of goods received in a particular week, divide unusable kilograms from that group by the group's total kilograms. Do not add losses from another period or missing containers. Use separate cause codes for mechanical damage, shelf life, ordering errors and temperature-related loss; leave the cause unknown where evidence is absent.
4. Container cycle runs from dispatch to readiness
For each container, record dispatch and the time it becomes ready again after return, inspection, cleaning and required preparation. An average of completed cycles alone can hide containers that have been with customers for a long time; also report the age of open cycles.
In a hypothetical steady flow, ten containers dispatched daily with an average three-day cycle means an average of 30 containers in the cycle. This is not an exact purchase quantity: assess peak days, reserves and unavailable units separately. See the container quantity calculation for the wider planning inputs.
5. Separate lost containers from overdue returns
Select a defined opening group and retain its container IDs. Count customer, transit, cleaning, repair, under-investigation and confirmed-lost statuses separately. Track containers purchased later as a separate group. An overdue return is investigated before it is recorded as a confirmed loss.
The 2022 Fraunhofer UMSICHT review recommends tracking rotations, breakage and loss for reusable plastic produce crates. Those fields can also help organise insulated-container records; establish targets from your own container group.
