dnom charts

**DNOM charts** is the **deviation-from-nominal SPC chart method that monitors how far each observation is from its product-specific target** - it supports short-run control across multiple part types with different nominal values. **What Is DNOM charts?** - **Definition**: Control charts based on transformed values equal to measured result minus nominal target. - **Primary Use**: Pooling short-run data from diverse products while preserving target-centric interpretation. - **Data Requirement**: Requires reliable nominal definitions and consistent measurement capability. - **Chart Behavior**: Centerline near zero indicates alignment with nominal target across products. **Why DNOM charts Matters** - **Short-Run Utility**: Allows SPC where each product lacks enough standalone data. - **Centering Focus**: Directly highlights systematic bias from intended target values. - **Operational Simplicity**: Easier to explain than more complex multivariate pooling methods. - **Cross-Product Insight**: Reveals shared setup or equipment bias affecting multiple product codes. - **Quality Protection**: Early target-shift detection reduces off-nominal output risk. **How It Is Used in Practice** - **Nominal Governance**: Maintain controlled target values and revision traceability. - **Chart Deployment**: Plot deviation values with limits derived from normalized process behavior. - **Action Rules**: Investigate persistent bias and adjust setup, calibration, or compensation logic. DNOM charts is **a practical short-run SPC technique for high-mix manufacturing** - target-deviation monitoring provides a clear and scalable way to detect cross-product centering issues.