Overview
EN ISO 18183-1:2024 - Geometrical product specifications (GPS) - Partition - Part 1: Vocabulary and basic concepts defines the foundational vocabulary and conceptual framework for applying partition to geometrical features in product specification and verification. Published by CEN and aligned with ISO 18183-1:2024, this part establishes terms and general rules used throughout the ISO 18183 series for partitioning features of the nominal model (design intent) and the non‑ideal surface model / skin model (measured physical interface).
Keywords: EN ISO 18183-1:2024, partition, GPS, partitioned features, feature uncertainty zone, nominal model, skin model, partition algorithms.
Key topics
- Core definitions: clear definitions for geometrical feature, partition, nominal model, non‑ideal surface model (skin model) and fuzzy set concepts used in partition.
- Feature uncertainty zone identity sets: introduction of fuzzy-set based realizations for features (surface, line, point) that represent uncertainty in specification and verification.
- Partition concepts and procedures: framework for determining a partition, including the role of partition information in the nominal model and criteria/methods used during partition.
- Partitioned feature types: treatment of feature discontinuity, feature transition, and other partitioned feature categories.
- Notation and modifiers: guidance on notation and how ISO GPS modifiers influence the initial set of partitioned features to match design intent.
- Relationship to measurement: distinction between partition applied to nominal models (specification) and partition applied to skin models (verification); acknowledgement that different partition algorithms can produce different feature identity sets.
Applications
EN ISO 18183-1:2024 is applicable where clear, consistent partitioning of geometric features is required:
- Preparing and interpreting GPS-compliant CAD/CAM specifications.
- Developing and validating partition algorithms in metrology and inspection software.
- Implementing measurement and verification routines for CMMs and scanning systems that map measured surfaces to partitioned features.
- Defining verification procedures where uncertainty and feature identity must be treated rigorously (e.g., tolerance analysis, conformity assessment).
Who should use this standard
- Metrologists and inspection engineers
- CAD/CAM/CAE and metrology software developers
- Quality assurance and manufacturing engineers working with GD&T and GPS
- Standards committees and technical writers producing specification documents
Related standards
This part provides the vocabulary and high-level concepts needed to ensure consistent, interoperable partitioning practices across specification and verification workflows in geometrical product specification (GPS).