Overview
ISO 7870-5:2014 - Control charts: Part 5, Specialized control charts provides guidance on selecting, using and interpreting specialized control charts where standard Shewhart methods are inadequate or less efficient. The standard helps practitioners apply statistical process control (SPC) techniques in special situations such as widely spaced samples, changing process averages, non-normal data, large sample sizes, or when different types of nonconformities have different criticality. It focuses on practical use - when to choose a specialized chart, how control limits are determined, and the chart’s advantages and limitations.
Key Topics
- Scope and definitions tied to ISO 3534-2 (vocabulary and symbols for applied statistics).
- List of specialized charts for variables data, including:
- Moving average and moving range charts
- z-charts
- Group control charts
- High–low control charts
- Trend control charts
- Control charts for coefficient of variation
- Control charts for non-normal data
- Specialized charts for attributes data, including:
- Standardized p-charts
- Demerit control charts
- Control charts for inspection by gauging (go/no‑go)
- Guidance provided for each chart:
- When to use it (use cases)
- How control limits are established
- Interpretation rules
- Advantages and limitations
- Worked examples illustrating application
- Terminology and symbols to standardize interpretation and implementation.
Applications and Who Uses It
ISO 7870-5 is intended for professionals applying SPC where standard Shewhart charts are not optimal:
- Quality engineers and process control specialists
- Industrial statisticians and data analysts
- Six Sigma practitioners and continuous improvement teams
- Manufacturing engineers (assembly, gauging, long-cycle processes)
- Service industry analysts dealing with non-normal or sparse data
Typical applications:
- Processes with long production intervals or one-observation subgroups (use moving average/moving range)
- Situations with systematic shifts in mean (trend or z-charts)
- Multiple subgroup sources or large sample sizes (group control charts)
- Attribute-based inspections with weighted nonconformities (demerit charts, standardized p-charts)
- Non-normal measurement distributions (specialized control charts for non-normal data)
Related Standards
- ISO 7870 series (general guidance and other parts):
- Part 1: General guidelines
- Part 2: Shewhart control charts
- Part 3: Acceptance control charts
- Part 4: Cumulative sum (CUSUM) control charts
- Part 6: EWMA control charts
- ISO 3534-2 (Statistics - Vocabulary and symbols - Part 2: Applied statistics)
ISO 7870-5:2014 is practical, example-driven guidance for adapting SPC to complex or atypical monitoring scenarios where specialized control charts deliver better detection of unnatural process variation.
