A cold-chain flow map shows where a shipment waits and for how long. It does not, by itself, prove that a wait caused a temperature deviation. Keep the plan, observed events and measurements in separate records.
What to record on the map
List stages from product preparation through delivery and end use. For each shipment, record the stage and location; planned start and finish; actual timestamps; waiting place and conditions; and the responsible role. If available, add product or ambient temperature, sensor ID, measurement time and a link to the device record. Mark estimates or missing data clearly; do not present them as measurements. FAO recommends describing operation stages through distribution and end use, and documenting monitoring and corrective actions. FAO: Control of operation
Compare plan with actual events
Keep planned times in one column and actual timestamps in another. With start and finish records, stage duration = finish - start; waiting between stages = next actual start - previous actual finish. Show total elapsed time beside the individual stage durations. Use your own shipment records as inputs: do not fill gaps or assign a number to time you did not measure.
Do not turn a deviation into a cause. If a wait overlaps with a temperature change, mark it as ‘observed during the same interval.’ Do not label it the cause based on timing alone. Check sensor placement and status, door openings, loading and unloading records, product-temperature measurements and corrective actions. If the records cannot distinguish the cause, leave it unconfirmed.
Choose the next action
Select the largest variance or a recurring waiting point, then name an owner and the record to review. On the next shipment, use the same timestamps and measurement point for comparison. Update the map when the route or work step changes.
