Mandatory triggers
| Event | Why the picture changes | What to do |
|---|---|---|
| Layout changes, extensions, new gates | heat gains and airflows change | full mapping of the zone |
| Replacing, relocating or adding air conditioners, evaporators, heating | the distribution of cold and heat changes | full mapping in the affected seasons |
| New racks, change in storage height | stratification and circulation change | mapping with a new height grid |
| Relocation or replacement of temperature monitoring devices | you must confirm that the new points reflect the risk | mapping or a justification based on data from the previous study |
| Cold room repairs: insulation, evaporator, refrigeration unit | equipment characteristics change | 24–72 h study with tests |
Triggers from monitoring results
The EEC Guideline considers re-mapping appropriate if monitoring reveals excursions beyond the operating ranges whose causes have not been identified. Signals to watch for in the monthly data review:
- recurring alarms at the same point at the same time of day;
- drift of a monitoring point’s mean temperature from season to season;
- increasing amplitude of daily fluctuations;
- longer recovery time of a cold room after the door is opened;
- complaints about product condition with no obvious cause.
According to the EEC Guideline, changing refrigeration equipment settings within the storage range does not require re-mapping. For example, changing a cold room setpoint from +5 °C to +4.5 °C with a +2…+8 °C range.
Risk analysis: a simple matrix
Score each zone on five factors from 1 to 3 points, add up the scores, and use the total to set the frequency of scheduled reviews.
| Factor | 1 point | 2 points | 3 points |
|---|---|---|---|
| Margin to limits in the last mapping | more than 2 °C | 1–2 °C | less than 1 °C |
| Dependence on the external environment | room inside a building | insulated warehouse | borders the outside, loading dock, roof |
| Deviations over the past year | none | isolated, with known cause | recurring or unexplained |
| Changes in warehouse operations | none | higher throughput | new processes, 24/7 operation |
| Product sensitivity | stable products | temperature-sensitive | vaccines, biologics, high value |
| Total score | Risk level | Guideline for scheduled re-mapping |
|---|---|---|
| 5–7 | low | upon changes and deviations; annual review of monitoring data |
| 8–11 | medium | scheduled study in the critical season every 2–3 years |
| 12–15 | high | annually in the critical season, or after every season with deviations |
Seasonal studies
For the initial mapping of a warehouse, the EEC Guideline recommends at least two studies: in summer and in winter. For re-mapping, it is sufficient to repeat the season in which the initial study and monitoring data show the smaller margin to the limits. A retained placement layout with numbered points makes results from different years comparable.
How to document the decision
- Annual review
Summary of monitoring data, deviations, and changes to premises and equipment.
- Risk assessment
Scores for each zone and a conclusion on whether mapping is needed.
- Decision
An approved plan: which zones, in which season, to what extent.
- Execution and comparison
A report comparing the results with previous ones and updating the monitoring points.
Frequently asked questions
How often should a warehouse be mapped?
The law sets no fixed frequency. Mapping is repeated based on risk analysis and assessment, and whenever the building or equipment changes. Many organizations set scheduled re-mapping every 1–3 years depending on the risk.
Is mapping needed after cold room repairs?
Yes, if the repair affected the insulation, evaporator, refrigeration unit or structure: the equipment characteristics change, and previous results no longer serve as evidence.
Do both seasons need to be repeated?
As a rule, it is enough to repeat the critical season, the one in which past data show the smaller margin to the limits.
What counts as a deviation with no identified cause?
An excursion beyond the operating limits that cannot be explained by door openings, equipment failure, a power outage or another documented cause.