# Can ISO GPS and ASME Torancing Systems Define the Same Functional Requirements?
## 1 Introduction
At the end of Section 2 of this paper, a comparison table that provides much more detail is given. Some differences between ASME Y14.5 and ISO 1101 are also shown in [18], but it shall be underlined that the latest editions of both standards, which are considered in this paper, are not compared in [18]. In both systems, there are several different default rules i.e., specification and interpretation rules that are not stated by particular indications in the drawings but are only enforced due to the selection of a particular tolerancing system that is indicated in the drawing title block. In both systems, specifications by tolerance zone and specifications by gauge are available. Specification by gauge is functionally oriented to assembly and enables the use of virtual boundaries that may be implemented by material (physical) or virtual (digital) gauges to examine a part's ability to mate with its respective counterpart. It is the task of each designer to determine the permissible size, form, orientation and location deviations, which, if not violated, allow an intended performance of a part. The aim of this paper was to investigate how tolerances may be allocated (specified) in both systems to secure identical permissible deviations of manufactured parts from their nominal geometrical models. There are two important cases:  
* Local design office (familiar with one system) has to develop a product for a global company working with another system;
* Local supplier working with one tolerancing system is forced to adopt technical product documentation from a global company prepared according to another tolerancing system. In both cases, the objective is to secure a part function. Below several specifications made according to ASME Y14.5 will be \"translated\" to specifications made according to the ISO GPS system notations. It should be noted that transformation from ASME Y14.5 to the ISO GPS notation without loss of the part's intended function (loss of coded information) may be performed in a significantly larger amount of cases than reverse conversion due to a new set of modifiers implemented in ISO 1101:2017 [7]. It was underlined in [2] that ISO 1101:2017 allows for more precise tolerance definitions that are independent of the view plane and also support digital threads for geometry assurance. One hundred and fifty ISO documents [5] currently form the ISO GPS system, but only about ten devoted to geometrical tolerancing are directly addressed to designers, manufacturers and quality staff involved in product development and production. They will be analyzed in this paper to find the ISO GPS system specifications that are equivalent to specifications given according to ASME Y14.5. The issue of changing specifications of geometrical tolerances indicated according to ASME Y14.5 to the ISO GPS system is important for industry. The survey results on the usage of ISO GPS and ASME Y14.5 standards shows that 20% of companies will, in the future, use both ASME Y14.5 and the ISO GPS system standards [14]. The role of tolerance information sharing through a product life cycle was carefully analysed in [19], with good remarks on the capability of computer-aided design tools. Particularly, it was stated that currently available CAD systems only partly support rule-based tolerance specifications and processing of tolerancing information is performed with many manual interventions. Most advanced CAD systems allow for checking, taking into account the particular tolerance system [19]. Currently, a user can select the ISO GPS system or ASME Y14.5 standard, but switching from one tolerance system to another will not update specified tolerance indications according to the selected system. Further development of the commercial software is required to automate such a transition.