6. Traceability, genealogy and quality (SPC)

Traceability answers: for this finished serial/lot, which raw-material lots, machines, operators, parameters and test results were involved (backward), and where did a suspect material lot end up (forward)? Essential in automotive (IATF 16949), pharma (GMP, 21 CFR Part 11 electronic records), food and aerospace — and for targeted recalls.

-- Genealogy: which finished serials used a suspect component lot?
WITH Tree AS (
    SELECT ChildLot, ParentSerial FROM mes.Consumption WHERE ChildLot = 'LOT-2026-0412'
    UNION ALL
    SELECT c.ChildLot, c.ParentSerial FROM mes.Consumption c JOIN Tree t ON c.ChildLot = t.ParentSerial
)
SELECT DISTINCT ParentSerial FROM Tree;

SPC (Statistical Process Control): control charts (X̄–R, I-MR) with control limits at ±3σ; rules (Western Electric/Nelson) flag out-of-control trends before parts go out of tolerance. Cp/Cpk measure process capability against specification limits (Cpk ≥ 1.33 a common target).