CUSUM vs Shewhart charts for small shift detection: 1-sigma shift takes 44 subgroups on Shewhart vs 10 on CUSUM. Decision framework + EWMA middle ground.
Step-by-step calculation of p-chart control limits with a worked PCB inspection example. Covers the variable sample size problem (exact, average-n, and standardized approaches), the np>=5 minimum, and the Laney p-prime chart for overdispersion.
When and how to use the I-MR (Individual Moving Range) control chart. Covers the five scenarios requiring individual charts, a complete worked example with control limit formulas (d2=1.128, D4=3.267), normality assumptions, and sensitivity comparison vs. X-bar R.
Decision tree for selecting the correct SPC control chart type. Covers variable vs. attribute data, subgroup size thresholds, p-chart and c-chart distribution requirements, CUSUM and EWMA alternatives, and common chart-type mismatches with real consequences.
Comparison of Cpk and Ppk process capability indices with worked example, formulas, and a decision table for which index to report in PPAP submissions, customer audits, and ongoing SPC monitoring. Includes diagnostic use of the Cpk-Ppk gap.
Decision framework for selecting between Western Electric Rules (4 tests, 1956) and Nelson Rules (8 tests, 1984) on SPC control charts. Covers false alarm rates, pattern recognition examples, and how to map each rule type to your reaction plan.
Step-by-step worked example for building an X-bar and R control chart from CNC manufacturing data. Includes A2, D3, D4 constants for n=5, control limit formulas, pattern rule application, and Cpk calculation.