Economic considerations in the assignment of manufacturing tolerances

The paper shows a method for economic impact evaluation in those productive situations where the values of the magnitude dimensions used in manufacturing (named as manufacturing targets) can differ from those values specified by design tolerances. Several cases in which manufacturing dimensions modi. cation is licit are analysed and an application model is proposed. This model is based on a productive process defined by four groups of parameters: design tolerances, manufacturing variability, measurement uncertainty and part quality rates obtained in accordance with design tolerances. The definition of a quantitative criterion is also proposed based on the use of mathematical tools which try to conjugate non-complexity and effectiveness in the results. This criterion also allows an assignment to be established for the manufacturing target values during the manufacturing process.