Not enough manufacturing supervisors, supply chain managers, or vaccine coordinators map their environments. However, you did a little research, figured that temperature mapping might be a good idea and want to learn the steps to be successful at it, which is awesome. So congrats!
We created this list of steps in part as a refresher to our 2011 article on Warehouse Mapping, as temperature mapping technology has changed, specifically with the rise of wireless monitoring options for manufacturing and warehouse supervisors.
Before you do anything (it's so essential you can't even consider it a step), document. Document, document, document. The more documentation, the better. So document.
Step 1: Determine who, where, when, and what.
Who: Will you perform it internally, or use a contractor?
Where: Are their multiple warehouses? Is this a contracted warehouse?
When: Will you map for multiple seasons in a year?
What: What are you mapping for? A temperature sensitive product? Some temperature sensitive products? Temperature and humidity sensitive products?
Step 2: Sensor distribution.
Whoa boy. It's tough to concretely make assumptions about sensor distribution, because every warehouse is different. Also, you don't measure the temperature of an area. Yup, that's right. Temperature measuring instruments measure temperature at one specific point. Your thermostat in your house is only telling you the temperature at the thermostat, not in the attic, the bathroom, or even 5 feet from the thermostat. It works the same way when temperature mapping. You need to have enough sample points, or distribute enough sensors, to be able to analyze the temperature of in all areas of your facility that you wish to map. The best thing to do is ask an expert. Whether that is your internal QA Manager, a Cold Chain Contractor, or a Temperature Mapping Firm, getting a good sense of where temperature sensors should go is essential to finding problem spots, seeing air flow, and understanding the micro climates within your facility.
Step 3: Pick the right data logger
Data loggers these days come with everything but a kitchen sink. Which one is right for you? If you've hired an outside contractor to map your environment for you, this isn't something you need to be as worried about (still ask questions about equipment, though). However, if you are doing the audit internally, it's best two know your application, length of time, and the data analysis that is important to you. We wrote a post on picking the right data logger a few months back. You should check it out.
Step 4: Sampling Rate (Snapshot Mapping vs. Long-term Mapping).
With the advent of temperature sensors that can log tens of thousands of data points, and the recent prevalence of wireless monitoring options, grabbing and dealing with "too much data" is less of an issue today than it was ten years ago. This being said, you should base your sample rate on how long you will be mapping for. That's why those words in the parenthesis are included.
Snapshot Mapping (AKA Short-term Mapping): This type of mapping project is short and sweet. You map for only a few hours to a couple of days, and get a focused set of information on your warehouse. Advantages? Data you can deal with, ability to see minor fluctuations. This type of mapping is great for those warehouses that store really temperature sensitive products, or that are susceptible to rapid changes in temperature at a moment's notice.
Long-term Mapping: Yup, the opposite of Short-term Mapping. Long-term Mapping is mapping your warehouse for an extended period of time, to see the fluctuations over weeks and even months that your products might go through. Some QA Managers will take a brief snapshot of their warehouse, find some problem spots, and then continue to monitor and map their environments with less loggers, for a longer period of time. When you are worried about seasons, HVAC systems, and thermal mass, you should consider Long-term Mapping your environment.
Step 5: Review the data.
The bare-bones of what you are looking for are minimum, maximum, and mean kinetic temperature of your products and your environment. With this data, you can sniff out most problem spots in your warehouse.
Step 6: Modify your environment.
Unless your warehouse scored an A+ on the temperature mapping test (be honest, it most likely had a few issues) you need to modify your environment, or what products are going in which environment. Sometimes this means roping off an "off-limits area," other times, it means fixing your HVAC system. You have the results, now implement them into your section of the supply chain.
Step 7: Test again.
Yup, do it all over again. Sometimes this means testing immediately after having made modifications. Often it can mean setting up temperature sensitive loggers in the problem spots of your warehouse. At other times it simply means documenting the results, and documenting when you will test again.
Last thing: did you remember to document?