TS ISO 7870-6

TS ISO 7870-6 is the standard that addresses EWMA control charts for statistical process control, with a focus on monitoring small shifts in the process mean. The EWMA approach relies not on a single isolated measurement, but on an exponentially weighted combination of prior sample means, which makes the direction of process change easier to see over time.

How EWMA works in process monitoring

EWMA stands for Exponentially Weighted Moving Average. In practice, it gives greater weight to the most recent sample and progressively less weight to older samples. This structure is intended to reveal gradual, small to moderate changes in the process average earlier than methods that react mainly to large, sudden departures. In general technical terms, it belongs to the established family of control charts used to monitor stability in manufacturing, service and other continuous processes.

What this part covers technically

• EWMA control charts used to detect small shifts in the process mean
• Evaluation of the process average as an exponentially weighted moving average of previous sample means
• Heavier weighting of recent samples, with diminishing contribution from older samples
• Use of statistical process control for faster identification of small to moderate shifts

Within the broader control-chart family, this part defines the EWMA method as a distinct monitoring approach with memory, unlike classic Shewhart-style charts that react more directly to individual points. The standard sets out this technical framework; interpretation in real applications still depends on the sampling plan, the data collected and the characteristics of the process being monitored.