With ISO 2768-1, some of the measurement discrepancies will be tolerated for your mechanical equipment. The ISO 2768-1 was a prepared by the technical committee back in 1989 that listed how much discrepancy is tolerated when it comes to dimensional measures for mechanical equipments. The purpose of this form of standard is to simplify the general tolerances for linear and angular dimensions.
Attaining accuracy is the most desirable task. However, because a lot of articles have to be produced, some discord between the dimensions is quite obvious. The ISO details how much tolerance is actually allowed. Getting this certification will allow you to stay within the linear and angular dimensional ranges in order to create the right product.