seven points on one side

**Seven points on one side** is the **run-rule signal where consecutive points remain above or below the centerline, indicating likely mean shift** - this pattern suggests non-random bias in process behavior. **What Is Seven points on one side?** - **Definition**: A run of seven consecutive observations all on one side of the centerline. - **Statistical Meaning**: Probability is low under symmetric common-cause conditions. - **Signal Type**: Detects sustained center displacement even when all points stay within control limits. - **Rule Placement**: Used in run-rule sets for early shift detection. **Why Seven points on one side Matters** - **Mean Shift Detection**: Identifies centering loss before extreme values appear. - **Yield Margin Protection**: Off-center operation increases specification-edge risk. - **Action Trigger**: Prompts targeted verification rather than passive monitoring. - **Process Discipline**: Reinforces rule-based response over subjective interpretation. - **Stability Maintenance**: Helps keep long runs aligned to intended process target. **How It Is Used in Practice** - **Run Monitoring**: Track same-side sequence length automatically in SPC dashboards. - **Event Correlation**: Check for recent changes in setup, maintenance, or raw material lots. - **Correction Control**: Recenter with controlled adjustment and verify return to balanced behavior. Seven points on one side is **a practical centerline-bias indicator in SPC** - responding to this run signal early reduces risk of prolonged shifted operation.