Although commercial off-the-shelf (COTS) systems are built from commercially available components, the design, testing and qualification of a rugged system or module must ensure that the components, and the system itself, can withstand harsh military environmental conditions. This process begins at the level of materials, seals, temperature and EMI factors, and includes connectors and fasteners, paints and finishes, maintenance and manufacturing issues. Modules and systems must pass testing for vibration, shock, temperature and other environmental conditions such as humidity.