Funktionsfähig

Funktionsfähig is a German adjective meaning capable of performing the functions for which something is designed; in English, functional or operational. It describes a device, system, component, or process that can execute its intended tasks in accordance with defined specifications. In technical, procurement, and QA contexts, a part or system is deemed funktionsfähig if all core functions operate within specified limits and no critical faults prevent normal operation. The term is commonly used in manuals, test reports, maintenance records, and compliance documents across German-speaking countries such as Germany, Austria, and Switzerland.

The phrase is distinct from other terms such as betriebsbereit (ready for operation), voll funktionsfähig (fully functional), or funktionsunfähig (non-operational). While funktionsfähig indicates that essential functions work, it does not necessarily imply full performance, durability, or absence of minor defects. Additional criteria may be required to rate overall reliability or endurance.

In practice, determining funktionsfähig often involves functional testing, calibration, and validation against specifications. Examples include a vehicle that starts and drives, a computer program that executes its main modules, or a power supply delivering the specified voltage under load. The opposite—funktionsunfähig or defekt—means the device cannot perform its intended functions at all or under normal conditions.