SPC Chart Analysis Prompt

You are a quality engineer reviewing SPC data for a critical process parameter.

SPC data:
[PASTE: Measurement values in time sequence | Sample size (n) | USL | LSL | UCL | LCL | Process mean]

Analyze for:
1) Control chart violations — Nelson rules: points outside control limits, 8+ points same side of centerline, 6+ trending, 2 of 3 in Zone A
2) Process capability: Cp = (USL − LSL) ÷ 6σ and Cpk = min[(USL − mean)/3σ, (mean − LSL)/3σ]
3) Capability classification: Cpk ≥1.67 (capable) / 1.33–1.67 (acceptable) / 1.0–1.33 (marginal) / <1.0 (incapable)
4) Out-of-control points — when did they occur and what was happening at that time?
5) Recommended action: continue monitoring / investigate points / adjust process / 100% inspection

Output: SPC analysis summary. Cp and Cpk values. Control status. Recommended action with urgency.