Overview
ISO/TS 15530-4:2008 - Geometrical Product Specifications (GPS) - Coordinate measuring machines (CMM): Technique for determining the uncertainty of measurement - Part 4: Evaluating task-specific measurement uncertainty using simulation - specifies requirements for using simulation-based Uncertainty Evaluating Software (UES) to determine task‑specific measurement uncertainty for CMMs. The Technical Specification describes what manufacturers must declare about UES capabilities, how users should provide input data, and what documentation and verification are required to produce GUM‑compliant uncertainty statements. It also gives informative descriptions of simulation techniques, testing procedures and example verification methods.
Key topics and requirements
- Scope declaration: UES suppliers must explicitly declare the software’s claimed scope - applicable CMM types, probe/accessory support, accounted CMM errors, environmental conditions, measurement strategies, feature types and operator effects.
- Influence quantities checklist: A normative checklist (Annex A) identifies which uncertainty contributors the UES models (e.g., CMM geometry, probing deviations, temporal/spatial temperature gradients). Ranges of validity (temperature, part/task spectrum, gradients) must be specified.
- Input specification: The manufacturer must state required input data and how it is obtained (calibrated artefacts, MPE values, GR&R/ANOVA or expert judgment for operator effects).
- Model transparency and documentation: Suppliers must document how influence quantities are modeled (probability distributions), how simulated samples produce uncertainty estimates, and essential model features to allow user verification.
- GUM compliance: Results must comply with the Guide to the expression of uncertainty in measurement (GUM), including coverage factor or confidence level; both combined standard uncertainty and expanded uncertainty may be presented.
- Testing and verification: The document describes methods for testing UES (including four complementary testing approaches) and provides informative annexes with descriptive examples and verification procedures.
Applications and users
ISO/TS 15530-4 is aimed at organizations and professionals involved in coordinate metrology who need reliable, task‑specific uncertainty statements:
- CMM manufacturers and UES developers - to document and verify simulation software and declare capabilities.
- Quality and metrology engineers - to generate GUM‑compliant uncertainty estimates for inspection tasks, conformity assessment (ISO 14253‑1), and process control.
- Accreditation bodies and calibration labs - to evaluate UES verification, perform comparative testing, and set acceptance criteria.
- OEMs and inspection specialists - to assess measurement risk for critical features, plan measurement strategies, and combine UES results with other uncertainty components.
Related standards
- Guide to the expression of uncertainty in measurement (GUM)
- ISO 14253‑1 (inspection by measurement - conformity decisions)
- ISO 10360‑1 (CMM vocabulary/tests)
- Other parts of ISO/TS 15530 (e.g., Part 3 on calibrated workpieces)
Keywords: ISO/TS 15530-4:2008, CMM, uncertainty evaluating software, UES, task-specific measurement uncertainty, simulation, GUM compliance, coordinate measuring machines, measurement uncertainty, verification.