ISO GPS 8015 Best practice

This blog is translated from German with DeepL.

What is ISO GPS 8015?

As already described in an earlier tip, ISO GPS 8015 is a collection of standards. This collection of standards provides rules with which parts can be mapped completely and unambiguously with regard to their function. With these technical product specifications, a component, if correctly defined, can be manufactured worldwide with the same result every time. GPS stands for “dimensional and geometric product specification and verification”.

Image: Members of the ISO “International Organization for Standardization”, as of 2019.
Source: Ichwan Palongengi – Public Domain

Is it worth switching to ISO GPS 8015?

Well, that’s a very good question; certainly in view of increasing globalization. However, this can only be answered by you in detail. In the previous field report No. 15, we talk about the change in the designation of surface roughness. This changeover has taken place over the last 16 years and has not yet been completed everywhere. Therefore, one should be aware that a conversion of the drawings to ISO GPS is not feasible overnight. There are a wide variety of issues to consider when converting drawings. Here are the three most important:

  1. Does the manufacturer know what I am talking about?

  2. Does the measurement engineer know what I’m talking about?

  3. Do I know what I am talking about?

    If an existing drawing is revised according to ISO GPS 8015, the new revision of the drawing will probably contain a more comprehensive description than the “current” drawing.

Example: Conversion of a drawing according to article ISO GPS 8015

What will the manufacturer think when he suddenly receives a drawing on which many more specifications (tolerances) are shown? If he is familiar with ISO GPS 8015, he will probably understand this and supply you with your parts as usual. If he is not familiar with ISO GPS, he will probably charge a higher price than before the standard was introduced. In such cases, we recommend talking to the supplier and informing him about the introduction of the standard. Also in case of internal production we recommend training for the production staff. 

Measurement technician

Both the manufacturer and the measuring technician must know what is actually required according to the drawing. Problems can arise here if incorrect measurements are made. Furthermore, the measuring technician must respect the specifications of ISO GPS 8015 on how the part is measured. Thus, there is a possibility that the measuring technician is not equipped with the required measuring tools, which could result in an increase in the price of the part. In the case of a new measurement according to ISO GPS 8015, perhaps a brief discussion with the metrologist should be scheduled. As an example, below are the different methods for measuring a bore.

Example of different drilling measurement methods

I (developer)

When a drawing of an existing part is converted to the new set of standards, the function must be clarified and understood in advance. A product specification should be created that maps the part in terms of its function with the appropriate rules. To achieve this, a “minor” explanation may be necessary.


The aim of the new product specification (new drawings) is not to complicate drawings, but to focus on unambiguity and completeness with regard to their function. For this purpose, a syntax and its semantics are used, and this must be understood by all concerned (manufacturer, measurement engineer and me). A certain amount of time is required for a conversion to ISO GPS 8015. This starts with the developer. He must understand the function of the part. However, also measurement technicians as well as the manufacturer must know what is meant by these signs of ISO GPS 8015. Currently, the following will certainly apply to all of them:

Manufacturer ⇒ Time for explanations

Measurement technician ⇒ time for explanations

I ⇒ Time for explanations

We at Gimelli Engineering AG think that a changeover makes sense in the longer term, since ISO GPS 8015 will become established as a worldwide standard. If an understanding of the signs and their meaning is established, it will certainly simplify the life of all persons concerned. Rework on affected parts, for example, will become unnecessary, as the manufacturer and metrologist will see their function on the drawing. Furthermore, in the future, it would be conceivable to skip the drawing creation step by setting dimensional and geometric product specifications directly in the CAD part. This could save time and money. If you have any questions about this topic, please do not hesitate to contact us.

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