How Does Warehouse Mapping Work?

In industries such as health care, pharmaceuticals and food, the line separating success and failure can be as little as half a degree Celsius. From vaccines to cosmetics and dental products to meat, fish and poultry, the need for accurate temperature-controlled storage 24/7/365 is vital to product integrity and consumers’ health and safety. Warehouse mapping offers a way to analyze the temperature and humidity zones of storage facilities, as well as come up with solutions to meet regulatory requirements over periods of time.

While it has been around for decades, warehouse mapping has been thrust into the spotlight over the past two years due to the high-profile cold storage requirements of many COVID-19 vaccines. As such, regulating bodies such as Health Canada, the U.S. Food & Drug Administration (FDA) and World Health Organization have continued to reinforce a “quality-by-design” approach to all warehouse storage and distribution good manufacturing practices (GMP).

How It Works

Like everything, it starts with a plan – a validation plan, in this case. This documented strategy will help interpret the data that’s produced through the mapping process, as well as serve as a reference guide throughout the validation. It will typically include things such as: 

• Objectives
• Roles/Responsibilities
• Activities
• Documentation Processes and Procedures
• Schedules
• Change Control (in the event adjustments or corrective actions to the equipment/system have to be made)

The validation plan will also identify an installation qualification (IQ) stage that involves collecting the relevant information on the area being measured, including dimensions, layouts (i.e. product that’s located near exterior surfaces, entrances, or ceilings could be impacted by ambient conditions) and, most importantly, HVAC and refrigeration systems. 

While mapping is not a requirement for an IQ, it should be performed before beginning the operational and performance qualification (OQ and PQ) stages which does require mapping. During the IQ, it’s important to complete inspections and checks on all relevant electrical and mechanical systems. This includes specific tests to determine acceptance criteria, which needs to be performed with a “pass/fail.” All system drawings must also be provided, as well as equipment and spare parts lists, as well as with full preventative maintenance program with intervals and procedures.   

Other requirements during the IQ stage include determining the environmental cleaning process and SOPs for the area being mapped, and ensuring all calibration certificates are provided for the various sensors/devices to operate the system.

Lastly, the temperature and humidity measurements will be taken with a test measuring device to indicate if the area for storage complies with the limits identified in the guideline. All of this must be approved from the quality assurance (QA) official or persons obtaining the qualification. The OQ/PQ should not be performed until full completion of the IQ has been accepted and approved.

Data Logging

Next, the OQ stage will determine the distribution of data loggers within the warehouse – importantly, while it is empty of product. Depending on the space, these sensors might be as close as six meters and as far as 30 meters apart. The goal here is to deploy them in a way that provides even distribution throughout all three dimensions of the space (up/down, left/right, front/back). Alpha Controls & Instrumentation has mapped warehouses as large as 50,000-square-feet that required as many as 100 loggers!

The data loggers will measure, record and transmit the data during the testing periods, which typically involves “door-open” and “power-off” tests that are performed during both peak winter and summer conditions. The key here is identifying any hot or cold zones, as well as how areas of the warehouse react to changes with the HVAC system. The zones will be triggered by alarms that are set off when temperatures approach, or fall outside of, a predetermined range.
These tests typically take place over 24 to 72 hours. They are followed by a report that identifies deviations and excursions, as well as recommended areas which may require further heating or cooling.  The entire process is then repeated for the PQ, which is performed over seven consecutive days with product now in the warehouse. 
Following the report, companies may choose to make changes to meet regulatory guidelines, after which they would have the area mapped again to confirm compliance (Note: this part of the mapping process is typically less intense, only taking one to two days).

There are plenty of additional considerations with warehouse mapping. In our next blog, we’ll tackle some of the important questions you should be asking, such as whether mapping is one-and-done, can companies map on their own and are all third-party service providers considered equal?