Rugged IT is a marketing term for hardware that is designed to operate in extremely harsh environments and conditions. There are three generally accepted levels of ruggedization: semi-rugged, fully-rugged and ultra-rugged. The levels describe a product's ability to survive drops, vibration, dust, immersion and extreme temperatures.
Semi-rugged devices, which are increasingly being called business-rugged by marketers, are usually enhanced versions of commercial off-the-shelf (COTS) hardware. The components are the same, but they are protected better. For example, a semi-rugged laptop might have a thicker case, a gel-mounted hard disk drive and a spill-resistant keyboard. Fully-rugged devices are designed from the inside-out to work in extreme temperatures, to be impervious to being dropped, to resist shocks and vibrations and to be dustproof and waterproof. A fully-rugged laptop may have a solid state hard drive, which has no moving parts, runs cool and doesn’t need for a fan. (another moving part that adds weight to the device.) Ultra-rugged devices, which are usually designed to meet precise specifications for military use, are made to handle the harshest environmental conditions. An ultra-rugged laptop can be left out in a sandstorm, frozen in a blizzard or sent on a vibrating rocket into space without any detrimental effects.
The levels of ruggardization are not standardized, which means that vendors have the freedom to use the labels as they see fit. Most vendors incorporate other values in their self-evaluations to provide potential customers with some assurance that their products deserve the label they have been given. The two most common values cited are from the Ingress Protection (IP) Code, a system for classifying the degrees of sealing protection provided by the enclosures of electrical equipment and MIL STD 810, a series of testing guidelines set by the U.S. Department of Defense for military and commercial equipment.
Matthew Elliot reviews several rugged laptops and explains more about how marketers promote their rugged products.
The Engineering ToolBox has more information about Ingress Protection Code (IP Code).
Secure Systems and Technologies has an overview of MIL STD 810.
Michael Morisy writes that "Rugged mobile devices must be more than durable in harsh environments."