Measurement uncertainty represents the possible errors associated with the equipment and the measurement techniques used during the testing of a product. Customer guardband represents any additional guardband considered necessary to ensure that a product meets the specifications. In the majority of cases, the customer guardband is zero. Characteristics and Supporting Specifications Characteristics describe product performance that is useful in the application of the product, but is not covered by the product warranty. Characteristic information is representative of the product and in many cases, it may be supplemental to a specification.
Characteristics are less structured than specifications.
In most cases, they do not include the guardbands that are part of the specifications. Typically, determination of characteristics occurs during product development and they are not necessarily verified on all units produced. A tolerance interval or proportion of a performance distribution derived from the measurement of a significant number of units. The quantity of a parameter covered by a specification, but over a narrower range of conditions. For example, a specification describes the performance of a parameter over the 0 to 50 C temperature range.