The apparatus shall continue to operate as intended. No degradation of performance or loss of function is allowed below a performance level specified by the manufacturer, when the apparatus is used as intended. In some cases the performance level may be replaced by a permissible loss of performance. If the minimum performance level or the permissible performance loss is not specified by the manufacturer, then either of these may be derrived from the product description and documentation and what the user may reasonably expect from the apparatus if used as intended.

This performance criteria is generally applied during RF disturbance, like radiated field and RF conducted disturbance.