A Quality Assurance Plan is a set of guidelines followed by the user of the equipment to insure accurate results.  It is sometimes referred to as a “maintenance program” or “maintenance protocol”.

Each jurisdiction defines its own policies for quality assurance.

For example, the U.S. Department of Transportation workplace testing program requires that the manufacturer of the breath testing instrument publish a QAP and have it approved by NHTSA (National Highway Traffic Safety Administration).  It also requires that the users of instruments in the DOT testing program follow the requirements of the QAP.