Manufacturing: Root-Cause Analysis Across the Supply Chain¶
Case study → manufacturing
Quality failures are causal systems, not isolated defects.
Manufacturing issues rarely have one cause. They propagate through process steps, tooling, suppliers, and environmental conditions. We make those chains explicit and auditable.
The question
How do we identify root causes of quality failures when evidence spans sensors, process logs, maintenance events, and supplier batches — and decisions must be justified?
Failure modes to avoid
Correlation traps
Spurious correlations appear in high-dimensional sensor data.
Missing context
Process step dependencies and maintenance history are often disconnected.
Non-reproducible investigations
Root-cause analysis becomes tribal knowledge without traces.
Unsafe actions
Line stops, recalls, and supplier blocks must be governed and reviewed.
What changes with causal chains
flowchart LR;
B["Batch"] --> S["Supplier event"];
S --> P["Process step"];
P --> Q["Quality signal"];
Q --> F["Failure"];Diagram: governed RCA workflow
flowchart TB;
I["Incident"] --> E["Collect evidence"];
E --> P["Generate causal path candidates"];
P --> V["Validate constraints + required evidence"];
V -->|"Pass"| A["Recommendation + trace"];
V -->|"Fail"| X["Abstain + request missing data"];Outputs
Root-cause paths
Mechanistic chains with evidence per edge and explicit assumptions.
Traceable interventions
Line adjustments, supplier actions, and mitigations tied to the trace artifact.
Faster postmortems
Investigations become repeatable and comparable over time.
Governed escalation
High-impact actions trigger review gates and mandatory sign-offs.