TS ISO 7870-9

TS ISO 7870-9 is the Turkish edition of a standard devoted to control charts used for monitoring stationary processes. It explains how such charts are constructed and applied when process behaviour is assumed to remain statistically stable over time. In general technical terms, control charts are one of the core tools of statistical process control, used to make shifts in process level or variation visible before they become larger quality problems.

What a stationary process control chart is meant to show

A stationary process is one that fluctuates randomly around a stable pattern without a systematic trend or drift. For this class of processes, control charts typically use a central line together with upper and lower control limits to track sample results over time. In practice, this helps users see whether a process is behaving as expected or whether a special cause may be present. The standard’s stated subject is the construction and application of these charts, not a single product sector, measurement type, or distribution model.

Role within statistical process control

The value of a control chart lies in distinguishing routine variation from unusual variation. For stationary processes, it supports early detection of shifts, sudden jumps, or emerging instability in manufacturing, service operations, and laboratory monitoring. The reference to ISO 3534-2 indicates that the document relies on shared statistical quality and process-monitoring terminology. In that sense, the standard sits within the broader language and method framework of statistical process control.

• Principles for constructing and using control charts in process monitoring
• Applicability to processes with stationary behaviour
• A statistical process control interpretation framework
• Terminology aligned with TS ISO 3534-2