Overview
ISO 18183-1:2024 - Geometrical product specifications (GPS) - Partition - Part 1: Vocabulary and basic concepts defines the foundational terminology and conceptual framework for applying a partition operation to geometrical features. It establishes the language and basic rules used when partitioning the nominal model (design intent) and the non‑ideal surface model (skin model) of a workpiece for specification and verification purposes. This part of the ISO 18183 series is focused on concepts (not detailed algorithms) and supports consistent interpretation of GPS partitioning across design, measurement and software tools.
Key Topics and Requirements
- Definitions and scope: Core terms such as partition, nominal model, non‑ideal surface model (skin model), single feature, compound feature, complete feature and restricted feature.
- Partition concepts: Framework for determining partitions, including the distinction between feature transition (design-intended meeting/merging of features) and feature discontinuity (unintentional break that cannot appear in the nominal model).
- Feature uncertainty zone identity sets: Introduces fuzzy‑set based identity sets representing feature presence in specification or verification:
- F2 - surface feature uncertainty zone identity set
- F1 - line feature uncertainty zone identity set
- F0 - point feature uncertainty zone identity set
- Partition operations vocabulary: Abstract operations used in ISO GPS workflows, such as selection, subdivision and simplification of partitioned features.
- Notation and information needed: Lists the data required to apply partition to nominal and skin models (geometrical data, partition modifiers, method and criteria).
- Conceptual relationships: How partition fits into the ISO GPS matrix model and influences chains of standards (notably chains B, C and E).
Practical Applications and Who Uses It
ISO 18183-1:2024 is intended for professionals and tools working with geometrical product specification and verification:
- Design engineers and CAD modelers - to specify partition intent in nominal models.
- Metrologists and quality engineers - to interpret and verify partitioned features on measured parts and skin models.
- CMM programmers and inspection software developers - to implement partition-aware algorithms and represent feature uncertainty zone identity sets.
- Manufacturing engineers and tolerance analysts - to align inspection strategies with design intent and GPS modifiers.
Real-world uses include interpreting GPS annotations in technical drawings, implementing partition rules in measurement software, and ensuring consistent verification of complex surfaces and feature transitions.
Related Standards
- ISO 17450-1 - Model for geometrical specification and verification
- ISO 22432 - Features utilized in specification and verification
- ISO 8015 - GPS fundamentals: concepts, principles and rules
- ISO 18183 series (Part 2: nominal model partition; Part 3: skin model partition)
Keywords: ISO 18183-1:2024, geometrical product specifications, GPS partition, nominal model, skin model, feature uncertainty zone, F2 F1 F0, partitioned features, ISO GPS.