Overview
ISO 22514-2:2026 is an international standard developed by ISO that specifies statistical methods for determining process capability and performance, particularly for time-dependent process models. This third edition extends established methods to real-world situations where process behavior may change over time and may not always be in statistical control. The standard is particularly relevant for the analysis of continuous quality characteristics across different industrial and economic sectors. ISO 22514-2:2026 helps organizations understand and quantify the performance of processes that exhibit time-dependent changes in quality characteristics, enabling informed decisions in quality management and process improvement.
Key Topics
- Time-Dependent Process Models: The standard details eight process distribution models classified according to the stability of the process mean (location) and variability (dispersion) over time. These models provide a foundation for properly categorizing and analyzing different process behaviors.
- Continuous Quality Characteristics: The described statistical methods are tailored for continuous data, common in manufacturing and process industries.
- Statistical Control vs. Out of Control: It distinguishes between processes in statistical control (stable processes) and those that are not, providing guidance on which capability (Cp, Cpk) or performance (Pp, Ppk) indices to use in different situations.
- Distribution Analysis and Model Selection: Emphasis is placed on selecting appropriate time-dependent distribution models using both graphical tools (control charts, probability plots) and statistical techniques (parameter estimation, analysis of variance).
- Calculation of Process Indices: Detailed procedures are provided for estimating process location (central tendency), dispersion (variability), and calculating corresponding process capability and performance indices. Different methods are recommended depending on data characteristics and distribution type.
- Reporting: Guidance is included for transparent reporting of process performance and capability indices, including the recommendation to report confidence intervals.
Applications
ISO 22514-2:2026 provides practical value for a variety of industrial and business applications:
- Manufacturing Quality Control: By enabling robust assessment of process capability even when processes are not perfectly stable, organizations can better identify areas needing improvement and monitor ongoing process performance.
- Statistical Process Management: The standard serves as a foundation for advanced process analysis, including the evaluation of processes with time-dependent or trending behavior.
- Process Optimization: Data-driven insights from the standard's methods inform decisions on adjustments, preventive maintenance, or redesign to maintain or improve process outputs.
- Small Batch or High Volume Production: The procedures are applicable to both large volumes of serial process results and smaller production series, making it versatile across different industries.
- Cross-Industry Use: Whether in automotive, electronics, chemicals, or service industries, ISO 22514-2:2026 supports quality professionals and process engineers in achieving higher levels of process control and product quality.
Related Standards
Implementing ISO 22514-2:2026 is most effective alongside key related standards:
- ISO 22514-1: General principles and concepts for statistical methods in process management.
- ISO 3534-2: Applied statistics vocabulary and symbols, providing terminology consistency.
- ISO 5479: Statistical tests for assessing normality of data distributions.
- ISO 7870 Series: Control charts for statistical process control, supporting process monitoring and stability assessment.
These related standards provide a comprehensive framework for integrated quality and process management using internationally recognized statistical methods.
Adopting ISO 22514-2:2026 equips organizations with best practices for the assessment of process capability in time-varying environments, supporting continuous improvement and alignment with quality management objectives across sectors.
Open preview (PDF)Statistical methods in process management — Capability and performance — Part 2: Process capability and performance of time-dependent process models