ABSTRACT
In the context of manufacturing, variation is the amount one or more measured values deviate from a speci¢ed value. It is the imperfection seen in actual asproduced parts, contrasted against the perfect models created in CAD and seen on drawings. In the context of design and speci¢cation, tolerances on the drawing set the limits for variation. In the context of tolerance analysis and tolerance stackups, variation must be considered from a speci¢cation point of view as well as a measured value point of view.
