For verification, it’s important to note that tests aren’t the only acceptable verification activities; a company can also utilize inspections and analyses for their requirements, which can sometimes be cheaper and/or less time-consuming than tests. Some examples of these alternate verifications include: “thermal analysis of an assembly to assure that internal or surface temperatures do not exceed specified limits” and “worst case analysis of an assembly to verify that components are derated properly and not subject to overstress during handling and use”. Of course, depending on the product these other avenues of verification may not be substantive enough, but it’s good to keep in mind other avenues.
http://www.fda.gov/downloads/MedicalDevices/…/ucm070642.pdf Page 39