Independence principle

The independence principle is a tolerance principle. Until a few years ago, the standardized standard among the tolerance principles was the enveloping principle. In 2011, the enveloping principle was abolished as a standard and the standardized validity of the independence principle was standardized instead. This states that dimensional, form, positional and surface tolerances must each be considered independently of one another. According to the rules of the ISO standards, the principle of independence generally applies whenever a different tolerance principle is not explicitly specified in a document by the corresponding standardized symbols and entries. Since this rule change has effectively standardized an almost opposite method of tolerancing compared to the abolished principle rules, it is imperative that the application of the envelope principle be adequately identified as such when using the old standard. It is also useful, even when using the currently standardized standard, to indicate with entries which tolerancing principle is to be applied to a process, since standards and standardization can change, making it difficult again to evaluate technical drawings if they follow the contemporary standards unmarked for reasons of normativity or convenience.