TS ISO 8258

TS ISO 8258 is the Turkish edition of a guidance standard on Shewhart control charts and their use in statistical process control. It focuses on the core logic of chart-based monitoring: tracking process behaviour over time with sampled data so that ordinary variation can be distinguished from unusual, assignable causes.

What the Shewhart method does in practice

In general technical terms, Shewhart control charts display a process using a central line and control limits, allowing users to see whether variation remains consistent with a stable process or begins to show non-random signals. The method is widely associated with manufacturing and other process environments because it helps reveal change early, before variability turns into larger quality loss. The underlying idea is not merely to plot data, but to interpret patterns in context.

What this document covers

According to its scope, the standard provides guidance for the use and understanding of the Shewhart control chart approach within methods for statistical control of a process. That makes it a conceptual and interpretive reference rather than a product specification or a test method for a single item. It helps users understand the relationship between process averages, dispersion, control limits, and signals that suggest the process may no longer be behaving as expected.

• Monitoring process variation over time
• Distinguishing common-cause behaviour from unusual signals
• Interpreting Shewhart charts within statistical process control
• Understanding the roles of the central line and control limits