Deviation

Difference between a characteristic value, or a value attributed to a characteristic, and a reference value.

For a qualitative characteristic: Characteristic value or value attributed to a characteristic minus the reference value.

translated from DIN 55350 - 12:1989-03

Reference Volume (and volume-specific, additional or differing definitions to the standard):
VDA volume "Standardized process for handling customers' complaints "

The "difference between the value of a characteristic and a reference value". In the case of quantitative characteristics the deviation is defined as "value of the characteristic minus the reference value". If the deviation exceeds the permitted/specified/agreed limits (see "Tolerance") this represents a failure (q.v.). With qualitative characteristics the same applies in principle – that is, a deviation from specified requirements represents a defect or failure.