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ISO GPS: Global language for measurement technology

Measurement News from Q-Tech

The world of manufacturing is full of complex processes and precise requirements that need to be met in order to deliver high-quality products. The ISO-GPS system (Geometric Product Specification) is a crucial tool in this process. But what exactly is ISO-GPS and why is it so important? This article gives you a comprehensive overview of the topic.

What is ISO GPS? ISO GPS is an international standard for defining and measuring product characteristics to ensure the quality and precision of components. The standard therefore serves as a globally uniform and clearly defined language.

Do you need support with the metrological implementation of the ISO GPS standard? No problem, use one of our individual training courses or simply contact our metrological real-time support. We will be happy to help you.

What is ISO GPS?

ISO-GPS is a normative system that defines geometric product specifications and associated test methods for manufactured objects. It was developed by the International Organization for Standardization (ISO) to ensure uniform and accurate specifications for the shape, orientation, position, surface texture and size of workpieces. It enables clear and unambiguous communication of technical requirements between all participants in the production chain.

History of ISO GPS

The history of the ISO-GPS system is a history of continuous development and adaptation to the growing needs of the manufacturing industry. The beginnings of the system date back to the 1980s, when the increasing complexity of manufacturing processes and the demand for higher quality and precision made a standardized system for describing and measuring product specifications necessary. The aim was to establish consistent rules that would allow geometric characteristics such as length, shape, direction, location or run to be described completely and unambiguously in technical specifications. 

ISO, the International Organization for Standardization, took up this challenge and began developing the GPS system. It was to become a globally accepted system that would simplify and improve the communication of technical specifications between manufacturers, suppliers and customers.

The first ISO GPS standard was published in 1994. It laid the foundations for the system and defined fundamental terms and concepts. Over the years, this first standard has been supplemented by a series of other standards covering various aspects of geometric product specification, from shape and position tolerances to surface finishes, dimensional systems and tolerance types.

However, the development of the ISO-GPS system was not a linear process. It was characterized by constant learning, adapting and improving, driven by feedback from the industry and the constant search for even better precision and quality. Every new standard, every update and improvement to the system was the result of intensive discussions and collaboration between experts from all over the world.

Today, almost three decades after its first publication, the ISO GPS system is more comprehensive and detailed than ever. It has become an indispensable tool for the manufacturing industry and plays a key role in ensuring product quality and precision.

The development of ISO-GPS is a perfect example of how international collaboration and continuous development can lead to outstanding results. In addition, it is a living system that continues to evolve and adapt to the needs of the manufacturing industry. It is exciting to see what developments the future holds for ISO-GPS.

Advantages of ISO GPS

Using the ISO-GPS system has numerous advantages. Here are some of the most important points:

  • Improved communication: By using a standardized system, technical data can be exchanged precisely and clearly between manufacturers, suppliers and customers. This reduces misunderstandings and improves collaboration.
  • Higher product quality: The exact specifications and tolerances of the ISO-GPS system enable precise control of product quality. This leads to fewer errors and a higher overall quality of the parts produced.
  • More efficient production: By clearly defining tolerances and specifications, the manufacturing process can be optimized. This results in fewer rejects and therefore more efficient production.
  • Uniform standards: As ISO-GPS is internationally recognized, it enables the comparability of products and processes worldwide. This is particularly important in the globalized manufacturing industry.
  • Legal security: Compliance with ISO GPS standards can also provide legal security, as they are often anchored as industry standards in regulatory requirements.
  • Improved customer relations: The use of ISO GPS can increase customer confidence as it is a sign of commitment to quality and precision.

These advantages make the ISO-GPS system a valuable tool in modern production.

Product specifications and tolerances

ISO-GPS defines standardized specifications and tolerances as a description of product characteristics. Tolerances are the accepted deviations from the ideal dimensions of a product. They are listed in technical drawings and can stand for size, shape, surface structure and position, for example.

They serve as a clear description of defined transitions between individual geometric elements. 

Shape and position tolerances

In the world of manufacturing, precision is of the utmost importance. Two important aspects of this precision are shape and position tolerances, which are standardized by the ISO-GPS system.

Shape tolerances are limit values defined in the ISO GPS standard for the deviation of a real shape from its ideal geometric shape.

For example, roundness, straightness, flatness and cylindricity can be described. The precision of these shapes is often critical to the function of a part. For example, a cylinder that is not exactly round could cause friction in a machine and ultimately lead to premature wear or failure.

Position tolerances, on the other hand, are deviation limits for the position of a feature in relation to a reference feature or system. Positional tolerances are critical to the correct assembly of parts as they ensure correct alignment and positioning. Without precise positional tolerances, parts may not fit correctly into an assembly, leading to malfunctions and failures.

Shape and position tolerances are crucial for the production of high-quality and functional components. Shape and position tolerancing enables precise control and measurement of product characteristics, contributes to the optimization of manufacturing processes and helps to prevent errors and defects.

However, it is important to note that the correct application of shape and position tolerances requires a thorough knowledge of ISO GPS standards. Misunderstandings or errors in application can lead to quality problems and product defects.

It is therefore important for anyone working in the manufacturing industry to understand the importance of shape and position tolerances and to keep up to date with the latest developments and standards in this area.

Technical drawing requirements

ISO-GPS places requirements on the presentation of specifications in technical drawings. This includes the correct use of symbols and annotations as well as the correct specification of tolerances. Nowadays, almost all digital programs for the creation of technical drawings (CAD) are already equipped with ISO-GPS interfaces, making it easy to create standard-compliant drawings.

This ensures that technical drawings are clear and easy to understand. Correct handling of technical drawings is important for both the designer and the production worker in order to avoid errors and misunderstandings. 

Geometric product specifications (GPS) Standards

The ISO GPS standards are made up of a large number of individual standards that cover all aspects of geometric product specification. The geometric product specification can therefore be described as a comprehensive set of standards. Each standard has a specific area of application and sets out requirements and guidelines for certain aspects of product specification and measurement.

Here are some examples:


It is a fundamental standard of the ISO GPS system. It defines general tolerances such as shape, orientation, position and run.

DIN EN ISO 21920

This standard specifies the indicators for surface roughness. It describes how roughness is to be indicated and measured on technical drawings.

DIN EN ISO 14405

This standard is the internationally valid drawing standard for dimensional tolerancing. As we at Q-Tech mainly deal with length measurement technology, ISO 14405 is one of the most important tolerancing principles in our company.

Basic rules for the use of ISO GPS

The use of ISO-GPS requires an understanding of the rules and principles of the system. For correct application, it is essential to know the various standards and to be able to interpret technical drawings correctly. Equally important is the ability to carry out measurements accurately and consistently. When carried out correctly, ISO-GPS is a decisive factor in ensuring the quality and precision of products.

Correct application of ISO GPS standards

The correct application of ISO GPS standards requires care and precision at an international level. Incorrect interpretations or measurement errors can lead to quality problems and product defects. It is therefore important that everyone involved receives thorough training and ongoing education. Companies should therefore invest in training their employees and ensure that they have the necessary knowledge and skills.

Compliance with the standard rules

Compliance with ISO GPS rules is crucial for quality assurance in manufacturing. It enables the accurate and repeatable measurement of product characteristics, reduces the risk of errors and helps to improve overall product quality. In addition, compliance with these rules is often a customer requirement or a legal requirement. It is therefore important for companies to carry out regular checks to ensure that the ISO GPS rules are being observed.

Consistent rules a decade after introduction

More than a decade after its introduction, ISO-GPS remains consistent and relevant. It is constantly reviewed and updated to meet the changing needs of the manufacturing industry and to ensure the quality and precision of products. The process shows that ISO-GPS is not a static system, but a constantly evolving tool that adapts to the needs of the industry.

One example:

With the introduction of ISO GPS standard 22081, older standards such as ISO 2768 T2 are no longer valid.

Nevertheless, almost a decade after the introduction of the first GPS standards, the system is still not sufficiently well known at international level.

The impact that ISO GPS has had on individual companies since its operational introduction cannot yet be clearly determined.


ISO-GPS is a valuable tool for the manufacturing industry. It enables the accurate and repeatable measurement of product characteristics, improves communication between manufacturers and customers and helps to improve product quality and efficiency. Although it is a complex system that requires a high level of expertise, it offers numerous benefits and remains relevant and important more than a decade after its introduction.

The correct application of and compliance with ISO-GPS standards are therefore crucial for success in the manufacturing industry. Nevertheless, it remains to be seen what long-term changes will come into effect as a result of the introduction of an intelligent tolerance management system.