Based on the idea of Zoutendijk, an iterative algorithm for the implicit minimum problem is proposed in this paper. Such a problem is encountered in dealing with the selection of standard deviations based on the minimum requirement of reliability. The optimal choice of standard deviation is followed by a proposed cost function which relates to the standard deviation in the form a1-sigma-1-n1 + a2-sigma-2-n2 + .... Three examples are given to show the capability of the proposed algorithm. Such an algorithm can be linked to the tolerance design or when deciding the standard deviation in quality control.